The mechanism of action of a citrus oil blend against Enterococcus faecium and Enterococcus faecalis.

AIMS: The aim was to explore the mechanisms by which a blend of orange (Citrus sinensis) : bergamot (Citrus bergamia) (1 : 1 v/v) EO (essential oil) (2% v/v) and its vapour (15 mg l(-1) air) brings about its antimicrobial effect against Enterococcus faecium and Enterococcus faecalis. METHODS AND RESULTS: Cells were exposed to the blend in oil or vapour form in a sealed unit. Membrane permeability was measured using an NPN assay and intra and extracellular ATP concentrations were assessed using luminescence. Assays using 3,3-dipropylthiacarbocyanine and carboxyfluorescein diacetate succinimidyl ester measured membrane potential and intracellular pH changes. TEM images of treated cells indicate morphological differences and show the possible uptake of the EO into the cell. After cells were exposed to EO or vapour, cell permeability increased by x2 and x40 respectively. A decrease of 1.5 in intracellular pH, 20 a.u. in membrane potential and 18 pmol mg(-1) protein of intracellular ATP occurred. CONCLUSIONS: The EO blend affects the cell membrane and cell homeostasis resulting in inhibition of growth or cell death. SIGNIFICANCE AND IMPACT OF THE STUDY: Understanding the mechanisms by which EOs bring about their antibacterial effect could lead to an alternative to chemical-based bactericides for use against Enterococcus sp.

In vitro inhibition of vancomycin-susceptible and vancomycin-resistant Enterococcus faecium and E. faecalis in the presence of citrus essential oils.

Glycopeptide-resistant Enterococcus (GRE) is an important healthcare-acquired infection (HCAI) which costs the healthcare service many millions of pounds worldwide. In this study, lemon (Citrus limon), sweet orange (Citrus sinensis) or bergamot (Citrus bergamia) essential oils (EO) and their vapours, alone and in combination, are tested for their antimicrobial activity against vancomycin-resistant and vancomycin-sensitive strains of E. faecium and E. faecalis. A blend of 1:1 (v/v) orange and bergamot EO was the most effective of the oils and/or blends tested with a minimum inhibitory concentration (MIC), at 25 degrees C and pH 5.5, of 0.25-0.5% (v/v) and a minimum inhibitory dose (MID) of 50 mg/L, at 50 degrees C at pH 7.5, when viable counts reduced by 5.5-10 log10 colony forming units (cfu)/mL, suggesting that this blend of citrus oils is effective under a range of conditions for inhibiting the growth and survival of E. faecalis, E. faecium and VRE.

Tai Chi: moving for better balance -- development of a community-based falls prevention program.

BACKGROUND: This study was designed to develop an evidence- and community based falls prevention program -- Tai Chi: Moving for Better Balance. METHODS: A mixed qualitative and quantitative approach was used to develop a package of materials for program implementation and evaluation. The developmental work was conducted in 2 communities in the Pacific Northwest. Participants included a panel of experts, senior service program managers or activity coordinators, and older adults. Outcome measures involved program feasibility and satisfaction. RESULTS: Through an iterative process, a program package was developed. The package contained an implementation plan and class training materials (ie, instructor's manual, videotape, and user's guidebook). Pilot testing of program materials showed that the content was appropriate for the targeted users (community-living older adults) and providers (local senior service organizations). A feasibility survey indicated interest and support from users and providers for program implementation. A 2-week pilot evaluation showed that the program implementation was feasible and evidenced good class attendance, high participant satisfaction, and interest in continuing Tai Chi. CONCLUSIONS: The package of materials developed in this study provides a solid foundation for larger scale implementation and evaluation of the program in community settings.

Translation of an effective tai chi intervention into a community-based falls-prevention program.

Tai chi--moving for better balance, a falls-prevention program developed from a randomized controlled trial for community-based use, was evaluated with the re-aim framework in 6 community centers. The program had a 100% adoption rate and 87% reach into the target older adult population. All centers implemented the intervention with good fidelity, and participants showed significant improvements in health-related outcome measures. This evidence-based tai chi program is practical to disseminate and can be effectively implemented and maintained in community settings.

Tai Chi-based exercise for older adults with Parkinson's disease: a pilot-program evaluation.

The primary objective of this study was to provide preliminary evaluation of the feasibility, safety, and efficacy of a newly developed Tai Chi-based exercise program for older adults with Parkinson's disease (PD). Using a one-group pretest-posttest design, 17 community-dwelling adults (mean age 71.51 years) with mild to moderate idiopathic PD (Stage I, II, or III on the Hoehn and Yahr scale) and stable medication use completed a 5-day, 90-min/day Tai Chi exercise-evaluation program. Outcome measures included face-to-face exit interviews on appropriateness and safety and physical performance (i.e., 50-ft speed walk, up-and-go, functional reach). At the end of this brief intervention, exercise adherence was 100% and the program was shown to be safe. Exit interviews indicated that the program was well received by all participants with respect to program appropriateness, participant satisfaction and enjoyment, and intentions to continue. Furthermore, a significant pretest-to-posttest change was observed at the end of the 5-day program in all three physical-performance measures (p < .05). The results of this pilot evaluation suggest that Tai Chi is an appropriate physical activity for older adults with PD and might also be useful as a therapeutic exercise modality for improving and maintaining physical function. These preliminary findings warrant further investigation.

The survival of three strains of Arcobacter butzleri in the presence of lemon, orange and bergamot essential oils and their components in vitro and on food.

AIMS: To test the effect of oils and vapours of lemon, sweet orange and bergamot and their components against three Arcobacter butzleri strains. METHODS AND RESULTS: The disc diffusion method was used to screen the oils and vapours against three strains of A. butzleri. In vitro bergamot was the most inhibitory essential oil (EO) and both citral and linalool were effective. On cabbage leaf, the water isolate was the least susceptible to bergamot EO, citral and linalool (1-2 log reduction), with the chicken isolate being the most susceptible (6-8 log reduction). However, the latter appeared not to be susceptible to vapours over 24 h although type strain and water isolate populations reduced by 8 logs. On chicken skin, the effectiveness of the oils was reduced compared with that on cabbage leaf. CONCLUSIONS: Bergamot was the most effective of the oils tested and linalool the most effective component. All strains tested were less susceptible in food systems than in vitro. SIGNIFICANCE AND IMPACT OF THE STUDY: Arcobacter isolates vary in their response to EO suggesting that the results of type strain studies should be interpreted with caution. Bergamot EO has the potential for the inhibition of this 'emerging' pathogen.

A novel, non-substrate-based series of glycine type 1 transporter inhibitors derived from high-throughput screening.

The synthesis and structure-activity relationships (SAR) of a series of indane and tetralin inhibitors of the type 1 glycine transporter, derived from a high-throughput screening (HTS) hit, are described. Key modifications that reduced the 5HT1B receptor affinity of the HTS hit and the P450 2D6 inhibition of subsequent analogues are delineated. While these modifications led to potent and selective GlyT1 inhibitors, HERG affinity and human microsomal clearance remain an issue for this series of compounds.

The effect of lemon, orange and bergamot essential oils and their components on the survival of Campylobacter jejuni, Escherichia coli O157, Listeria monocytogenes, Bacillus cereus and Staphylococcus aureus in vitro and in food systems.

AIMS: To investigate the effectiveness of oils and vapours of lemon (Citrus limon), sweet orange (Citrus sinensis) and bergamot (Citrus bergamia) and their components against a number of common foodborne pathogens. METHODS AND RESULTS: The disc diffusion method was used to screen the oils and vapours against Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, Escherichia coli O157 and Campylobacter jejuni. The survival of each species, demonstrated to be susceptible in the in vitro studies, was tested on cabbage leaf for 60 s by direct contact and on chicken skin for 10 min by direct contact and 24 h by vapour. The results indicate that bergamot was the most inhibitory essential oil (EO) and citral and linalool mimicked its effect (P > 0.001). Citral and linalool vapours produced 6 log reductions in L. monocytogenes, Staph. aureus and B. cereus populations on cabbage leaf after 8-10 h exposure but bergamot vapour exposure, while producing a similar reduction in L. monocytogenes and B. cereus populations, had no effect on Staph. aureus. CONCLUSIONS: Bergamot was the most effective of the oils tested and linalool the most effective anti-bacterial component. Gram-positive bacteria were more susceptible than Gram-negative bacteria in vitro, although Camp. jejuni and E. coli O157 were inhibited by bergamot and linalool oils and by linalool vapour. All bacteria tested were less susceptible in food systems than in vitro. Of the Gram-positive bacteria tested Staph. aureus was the least susceptible to both the oils and the components tested. SIGNIFICANCE AND IMPACT OF THE STUDY: Results suggest the possibility that citrus EOs, particularly bergamot, could be used as a way of combating the growth of common causes of food poisoning.

Improving physical function and blood pressure in older adults through cobblestone mat walking: a randomized trial.

OBJECTIVES: To determine the relative effects of cobblestone mat walking, in comparison with regular walking, on physical function and blood pressure in older adults. DESIGN: Randomized trial with allocation to cobblestone mat walking or conventional walking. SETTING: General community in Eugene, Oregon. PARTICIPANTS: One hundred eight physically inactive community-dwelling adults aged 60 to 92 (mean age+/-standard deviation=77.5+/-5.0) free of neurological and mobility-limiting orthopedic conditions. INTERVENTION: Participants were randomized to a cobblestone mat walking condition (n=54) or regular walking comparison condition (n=54) and participated in 60-minute group exercise sessions three times per week for 16 consecutive weeks. MEASUREMENTS: Primary endpoint measures were balance (functional reach, static standing), physical performance (chair stands, 50-foot walk, Up and Go), and blood pressure (systolic, diastolic). Secondary endpoint measures were Short Form-12 physical and mental health scores and perceptions of health-related benefits from exercise. RESULTS: At the 16-week posttest, differences between the two exercise groups were found for balance measures (P=.01), chair stands (P<.001), 50-foot walk (P=.01), and blood pressure (P=.01) but not for the Up and Go test (P=.14). Although significant within-group changes were observed in both groups for the secondary outcome measures, there were no differences between intervention groups. CONCLUSION: Cobblestone mat walking improved physical function and reduced blood pressure to a greater extent than conventional walking in older adults. Additional benefits of this walking program included improved health-related quality of life. This new physical activity may provide a therapeutic and health-enhancing exercise alternative for older adults.

Tai Chi and fall reductions in older adults: a randomized controlled trial.

BACKGROUND: The authors' objective was to evaluate the efficacy of a 6-month Tai Chi intervention for decreasing the number of falls and the risk for falling in older persons. METHODS: This randomized controlled trial involved a sample of 256 physically inactive, community-dwelling adults aged 70 to 92 (mean age, 77.48 years; standard deviation, 4.95 years) who were recruited through a patient database in Portland, Oregon. Participants were randomized to participate in a three-times-per-week Tai Chi group or to a stretching control group for 6 months. The primary outcome measure was the number of falls; the secondary outcome measures included functional balance (Berg Balance Scale, Dynamic Gait Index, Functional Reach, and single-leg standing), physical performance (50-foot speed walk, Up&Go), and fear of falling, assessed at baseline, 3 months, 6 months (intervention termination), and at a 6-month postintervention follow-up. RESULTS: At the end of the 6-month intervention, significantly fewer falls (n=38 vs 73; p=.007), lower proportions of fallers (28% vs 46%; p=.01), and fewer injurious falls (7% vs 18%; p=.03) were observed in the Tai Chi group compared with the stretching control group. After adjusting for baseline covariates, the risk for multiple falls in the Tai Chi group was 55% lower than that of the stretching control group (risk ratio,.45; 95% confidence interval, 0.30 to 0.70). Compared with the stretching control participants, the Tai Chi participants showed significant improvements (p<.001) in all measures of functional balance, physical performance, and reduced fear of falling. Intervention gains in these measures were maintained at a 6-month postintervention follow-up in the Tai Chi group. CONCLUSIONS: A three-times-per-week, 6-month Tai Chi program is effective in decreasing the number of falls, the risk for falling, and the fear of falling, and it improves functional balance and physical performance in physically inactive persons aged 70 years or older.

Falls self-efficacy as a mediator of fear of falling in an exercise intervention for older adults.

This study examined the role of falls self-efficacy as a potential mediator of the exercise and fear-of-falling relationship. The study sample involved 256 community-dwelling older adults aged 70-92 years (M = 77.48, SD = 4.95) who were recruited from a local health care system in Portland, Oregon, and participated in either a Tai Chi (n = 125) or a stretching control (n = 131) exercise intervention, three times per week, for 6 consecutive months. Measures of falls self-efficacy and fear of falling were assessed at baseline and at 3-month and 6-month follow-ups. Intention-to-treat analyses were conducted to evaluate the hypothesis of falls self-efficacy as a mediator of change in fear of falling that resulted from the 6-month Tai Chi intervention. Results supported the mediational hypothesis in that Tai Chi participants, who evidenced improvement in falls self-efficacy over the course of the intervention, reported greater reductions in fear of falling, compared with those in the stretching control condition. Results suggest that exercise interventions designed to improve falls self-efficacy are likely to reduce fear of falling in older adults.

Tai Chi: improving functional balance and predicting subsequent falls in older persons.

PURPOSE: To determine whether improved functional balance through a Tai Chi intervention is related to subsequent reductions in falls among elderly persons. METHODS: Two hundred fifty-six healthy, physically inactive older adults aged 70-92 (mean age +/- SD = 77.48 +/- 4.95), recruited from a local health system in Portland, OR, participated in a 6-month randomized controlled trial, with allocation to Tai Chi or exercise stretching control, followed by a 6-month postintervention follow-up. Functional balance measures included Berg balance scale, dynamic gait index, and functional reach, assessed during the 6-month intervention period (baseline, 3-month, and 6-month intervention endpoint) and again at the 6-month postintervention follow-up. Fall counts were recorded during the 6-month postintervention follow-up period. Data were analyzed through intention-to-treat analysis of variance and logistic regression procedures. RESULTS: Tai Chi participants who showed improvements in measures of functional balance at the intervention endpoint significantly reduced their risk of falls during the 6-month postintervention period, compared with those in the control condition (odds ratio (OR), 0.27, 95% confidence interval (CI), 0.07-0.96 for Berg balance scale; OR, 0.27, 95% CI, 0.09-0.87 for dynamic gait index; OR, 0.20, 95% CI, 0.05-0.82 for functional reach). CONCLUSIONS: Improved functional balance through Tai Chi training is associated with subsequent reductions in fall frequency in older persons.

Tai chi and self-rated quality of sleep and daytime sleepiness in older adults: a randomized controlled trial.

OBJECTIVES: To determine the effectiveness of tai chi on self-rated sleep quality and daytime sleepiness in older adults reporting moderate sleep complaints. DESIGN: Randomized, controlled trial with allocation to tai chi or exercise control. SETTING: General community. PARTICIPANTS: One hundred eighteen women and men aged 60 to 92. INTERVENTION: Participants were randomized into tai chi or low-impact exercise and participated in a 60-minute session, three times per week, for 24 consecutive weeks. MEASUREMENTS: Primary outcome measures were the seven subscales of the Pittsburgh Sleep Quality Index (PSQI), PSQI global score, and Epworth Sleepiness Scale (ESS). Secondary outcome measures were physical performance (single leg stand, timed chair rise, 50-foot speed walk) and 12-item short form (SF-12) physical and mental summary scores. RESULTS: Tai chi participants reported significant improvements in five of the PSQI subscale scores (sleep quality, sleep-onset latency, sleep duration, sleep efficiency, sleep disturbances) (P<.01), PSQI global score (P=.001), and ESS scores (P=.002) in comparison with the low-impact exercise participants. Tai chi participants reported sleep-onset latency of about 18 minutes less per night (95% confidence interval (CI)=-28.64 to -7.12) and sleep duration of about 48 minutes more per night (95% CI=14.71-82.41) than low-impact exercise participants. Tai chi participants also showed better scores in secondary outcome measures than low-impact exercise participants. Both groups reported improvements in SF-12 mental summary scores. CONCLUSION: Older adults with moderate sleep complaints can improve self-rated sleep quality through a 6-month, low- to moderate-intensity tai chi program. Tai chi appears to be effective as a nonpharmacological approach to sleep enhancement for sleep-disturbed elderly individuals.

Delineating the impact of Tai Chi training on physical function among the elderly.

BACKGROUND: Through a re-analysis of a Tai Chi intervention data set, the study objective was to determine which, if any, subgroups of the study sample evidenced differential benefits from the intervention. METHOD: Re-analysis of a Tai Chi intervention study, a randomized controlled trial in Eugene and Springfield, Oregon. Physically inactive participants aged > or =65 years were randomly assigned to one of two groups: Tai Chi (n=49) and a wait-list control (n=45). The main outcome measure was self-reported physical function. RESULTS: Initial latent curve analyses indicated significant Tai Chi training effects: Participants in the Tai Chi group reported significant improvements in perceived physical function compared to those in the control group. However, there was significant interindividual variability in response to Tai Chi. The overall intervention effect was further delineated by identifying two subgroups. This delineation showed that Tai Chi participants with lower levels of physical function at baseline benefited more from the Tai Chi training program than those with higher physical function scores. Inclusion of additional measures of individual characteristics at baseline, change in movement confidence, and class attendance further explained differences in treatment responses. CONCLUSIONS: Findings from this study suggest that although an intervention may show an overall effect (or no overall effect), it may be differentially effective for subgroups of participants that differ in their pre-intervention characteristics. Examination of variability in outcome measures can provide important information for refining and tailoring appropriate interventions targeted to specific subgroups.

An evaluation of the effects of Tai Chi exercise on physical function among older persons: a randomized contolled trial.

This study was designed to determine whether a 6-month Tai Chi exercise program can improve self-reported physical functioning limitations among healthy, physically inactive older individuals. Ninety-four community residents ages 65 to 96 (Mage = 72.8 years, SD = 5.1) volunteered to participate in the study. Participants were randomly assigned to either a 6-month experimental (Tai Chi) group (n = 49), which exercised twice per week for 60 min, or a wait-list control group (n = 45). A 6-item self-report physical functioning scale, assessing the extent of behavioral dysfunction caused by health problems, was used to evaluate change in physical functioning limitations as a result of Tai Chi intervention. Results indicated that compared to the control group, participants in the Tai Chi group experienced significant improvements in all aspects of physical functioning over the course of the 6-month intervention. Overall, the experimental group had 65% improvement across all 6 functional status measures ranging from daily activities such as walking and lifting to moderate-vigorous activities such as running. It was concluded that the 6-month Tai Chi exercise program was effective for improving functional status in healthy, physically inactive older adults. A self-paced and self-controlled activity such as Tai Chi has thepotential to be an effective, low-cost means of improving functional status in older persons.

Tai Chi, self-efficacy, and physical function in the elderly.

Using Tai Chi as an exercise mode, this study examined the association between self-efficacy and physical function. Ninety-four healthy, physically inactive older adults (M age = 72.8 years, SD = 5.1) were randomly assigned to either a 6-month, twice a week, Tai Chi condition or a wait-list control condition. Outcome variables included self-reports of movement efficacy and physical function assessed at baseline, middle, and termination of the study. Multisample latent curve analyses revealed a significant rate of change attributable to the Tai Chi intervention in both self-efficacy and physical function, with participants experiencing significant improvements over the course of the intervention. Analyses also showed a positive association between self-efficacy and physical function, indicating that improvements in older adults' self-efficacy of movement as a function of Tai Chi were related to increased levels of perceived physical capability. This study uncovered the need for further exploration of the relationship between exercise self-efficacy and physical function for enhancing health-related quality of life in older adults.

Enhanced type I immune response to a hepatitis B DNA vaccine by formulation with calcium- or aluminum phosphate.

DNA vaccines induce protective humoral and cell-mediated immune responses in several animal models. When compared with conventional vaccines, however, DNA vaccines often induce lower antibody titers. We have now found that formulation of a DNA vaccine encoding hepatitis B surface antigen with calcium- or aluminum phosphate adjuvants can increase antibody titers by 10-100-fold and decrease the immunogenic dose of DNA by 10-fold. Furthermore, boosting an HBs protein-primed response with the adjuvanted DNA vaccine resulted in a dramatic increase in the HBs-specific IgG2a response reflecting a shift towards a TH1 response. The mechanism by which aluminum phosphate exerts its adjuvant effect is not through increased expression of HBsAg in vivo; rather, the adjuvant appears to increase the number and affinity of HBs peptide antigen-specific IFN-gamma and IL-2 secreting T cells.

Medicinal herbs in the United States: research needs.

Virtually all cultures have, throughout history, used a variety of plants or materials derived from plants for the prevention and treatment of disease. Evidence of the beneficial therapeutic effects of these medicinal herbs is seen in their continued use. Additionally, the development of modern chemistry permitted the isolation of chemicals from medicinal herbs that have served as drugs or starting materials for the synthesis of many important drugs used today. Many more modern drugs have been synthesized as a result of knowledge gained from studies of mechanisms of actions of chemicals first isolated from medicinal herbs. Thus, medicinal herbs have played a major role in the development of modern medicine and continue to be widely used in their original form. Whereas it is generally agreed that most medicinal herbs are safe under the conditions used, some are toxic and should be avoided even though they are readily available, and others have significant adverse side effects when misused. Also, little has been done to investigate potential adverse effects that may be associated with extended or high-dose use of medicinal herbs. Thus, concern has been expressed that the lack of quality control used in the preparation of medicinal herbs, plus their unregulated sale and uninformed use, pose potential adverse health effects for consumers. There is also concern regarding potential herb/herb or herb/drug interactions and possible untoward health effects of medicinal herbs in sensitive subpopulations such as the young and the elderly and certain genetically predisposed individuals. In this paper, we discuss these concerns at some length and make recommendations for additional research and education discussed in the recent International Workshop to Evaluate Research Needs on the Use and Safety of Medicinal Herbs.

Sustained production of beta-glucuronidase from localized sites after AAV vector gene transfer results in widespread distribution of enzyme and reversal of lysosomal storage lesions in a large volume of brain in mucopolysaccharidosis VII mice.

The lysosomal storage disorders are a large group of inherited diseases that involve central nervous system degeneration. The disease in the brain has generally been refractory to treatment, which will require long-term correction of lesions dispersed throughout the central nervous system to be effective. A promising approach is somatic gene therapy but the methods have so far been inadequate because they have only achieved short-term or localized improvements. A potential approach to overcome these limitations is to obtain sustained high level expression and secretion of the missing normal enzyme from a small group of cells for export to neighboring diseased cells, which might allow the therapeutic protein to reach distal sites. We tested this in a mouse model of mucopolysaccharidosis VII (Sly disease) using an adeno-associated virus vector. After a single treatment the vector continuously produced the normal enzyme from infected cells at the injection sites. The secreted enzyme was disseminated along most of the neuraxis, resulting in widespread reversal of the hallmark pathology. An extensive sphere of correction surrounding the transduction sites was created, suggesting that a limited number of appropriately spaced sites of gene transfer may provide overlapping spheres of enzyme diffusion to cover a large volume of brain tissue.