Exploring Race Differences in Satisfaction With Rehabilitation Following Total Knee Arthroplasty: A Qualitative Study.

BACKGROUND: The purpose of this qualitative focus group study was to explore race differences in the rehabilitation experience and satisfaction with rehabilitation following total knee arthroplasty (TKA). METHOD: We conducted a series of qualitative focus group discussions with groups of non-Hispanic White and non-Hispanic Black older adults who recently underwent TKA. We used grounded theory approach, which asks the researcher to develop theory from the data that are collected. Participants discussed barriers and facilitators to accessing rehabilitation after surgery, opinions regarding their physical therapists, the amount of postoperative physical therapy received, and overall satisfaction with the postoperative rehabilitation process. RESULTS: Thirty-six individuals participated in focus groups. Three major themes emerged: (i) Participants reported overall positive views of their post-TKA rehabilitation experience. They particularly enjoyed one-on-one care, the ability to participate in "prehabilitation," and often mentioned specific interventions they felt were most helpful in their recovery. (ii) Despite this, substantial barriers to accessing physical therapy exist. These include suboptimal pain management, copayments and other out-of-pocket costs, and transportation to visits. (iii) There were minor differences in the rehabilitation experiences between Black and White participants. Black participants reported longer paths toward surgery and occasional difficulty interacting with rehabilitation providers. CONCLUSIONS: Individuals undergoing TKA can largely expect positive rehabilitation experiences postoperatively. However, some barriers to postoperative physical therapy exist and may differ between Black and White patients. Physical therapists should increase their awareness of these barriers and work to minimize them whenever possible.

Race Differences in Postacute Physical Therapy Utilization and Patient-Reported Function After Total Knee Arthroplasty.

OBJECTIVE: This observational cohort study included patients of Black and White race and non-Hispanic ethnicity with end-stage knee osteoarthritis who were scheduled to receive total knee arthroplasty (TKA) surgery. Our objective was to examine whether race differences exist in the use of physical therapy (PT) across all postacute settings and to examine patient-reported physical function following TKA. METHODS: We collected pre- and postoperative physical function data and postoperative rehabilitation data on 104 Black and White individuals undergoing TKA. Regression analyses and independent samples t-tests were used to explore the predictive value of race on postoperative functional outcome and to compare PT utilization within each postacute setting and across all postacute rehabilitation settings. RESULTS: Total PT received was similar between White and Black participants, but significant race differences in PT utilization existed within specific settings. Race did not significantly predict function after TKA, but Black participants had slightly lower self-reported function both before and after surgery than White participants. CONCLUSION: This is the first study to examine both PT utilization and functional outcomes in a sample of individuals undergoing TKA, and results indicate differences in where postoperative PT is received between Black and White patients.

One-year outcomes following physical therapist-led intervention for chronic hip-related groin pain: Ancillary analysis of a pilot multicenter randomized clinical trial.

Evidence related to physical therapist-led intervention for patients with chronic hip-related groin pain (HRGP) is limited. The purpose was to assess sustainability of treatment effects for people with HRGP undergoing two physical therapist-led interventions. We completed an ancillary analysis of a pilot multicenter, randomized clinical trial. Forty-six patients with chronic HRGP, 15-40 years, were enrolled. Patients were randomized to participate in 10 sessions over 12 weeks of either movement pattern training (MoveTrain) or traditional strength/flexibility (Standard). Participants completed self-report questionnaires before treatment and 6 and 12 months after treatment completion. Outcome measures included Hip disability and Osteoarthritis and Outcome Score (HOOS), Patient Specific Functional Scale and Numeric Pain Rating Scale for average and worst pain. Continuous data were analyzed with mixed model repeated measures analysis of variance (RM-ANOVA) within each group. Numeric pain rating scale (NPRS) was analyzed using multinomial generalized estimating equations (GEE) with a cumulative logit. Reported p values are from statistical contrasts within the RM-ANOVAs and GEEs testing a priori hypotheses regarding change from pretest to month 6, and pretest to month 12. A total of 43/46 (93.5%) participants completed treatment, 40 (87.0%) completed 6 and 38 (82.6%) completed 12 month questionnaires. At 6 and 12 months, both groups demonstrated clinically significant improvements, compared to pretest, in all subscales of HOOS (p < 0.01), Patient Specific Functional Scale (p < 0.001), and NPRS (p < 0.0001). Among patients with chronic HRGP, both MoveTrain and Standard resulted in improved outcomes that were sustained 12 months after treatment. Further investigation in a larger sample is needed to confirm our findings.

Implementing stratified care for acute low back pain in primary care using the STarT Back instrument: a process evaluation within the context of a large pragmatic cluster randomized trial.

BACKGROUND: Although risk-stratifying patients with acute lower back pain is a promising approach for improving long-term outcomes, efforts to implement stratified care in the US healthcare system have had limited success. The objectives of this process evaluation were to 1) examine variation in two essential processes, risk stratification of patients with low back pain and referral of high-risk patients to psychologically informed physical therapy and 2) identify barriers and facilitators related to the risk stratification and referral processes. METHODS: We used a sequential mixed methods study design to evaluate implementation of stratified care at 33 primary care clinics (17 intervention, 16 control) participating in a larger pragmatic trial. We used electronic health record data to calculate: 1) clinic-level risk stratification rates (proportion of patients with back pain seen in the clinic over the study period who completed risk stratification questionnaires), 2) rates of risk stratification across different points in the clinical workflow (front desk, rooming, and time with clinician), and 3) rates of referral of high-risk patients to psychologically informed physical therapy among intervention clinics. We purposively sampled 13 clinics for onsite observations, which occurred in month 24 of the 26-month study. RESULTS: The overall risk stratification rate across the 33 clinics was 37.8% (range: 14.7-64.7%). Rates were highest when patients were identified as having back pain by front desk staff (overall: 91.9%, range: 80.6-100%). Rates decreased as the patient moved further into the visit (rooming, 29.3% [range: 0-83.3%]; and time with clinician, 11.3% [range: 0-49.3%]. The overall rate of referrals of high-risk patients to psychologically informed physical therapy across the 17 intervention clinics was 42.1% (range: 8.3-70.8%). Barriers included staffs' knowledge and beliefs about the intervention, patients' needs, technology issues, lack of physician engagement, and lack of time. Adaptability of the processes was a facilitator. CONCLUSIONS: Adherence to key stratified care processes varied across primary care clinics and across points in the workflow. The observed variation suggests room for improvement. Future research is needed to build on this work and more rigorously test strategies for implementing stratified care for patients with low back pain in the US healthcare system. TRIAL REGISTRATION: Trial registration: ClinicalTrials.gov ( NCT02647658 ). Registered January 6, 2016.

Cardiovascular stress reactions in recent- and long-retired rugby players when watching a game.

While hospital admissions for cardiac causes on a population level appear to rise when the national team is playing in a sporting fixture, little research has examined cardiovascular reactions in spectators watching a sporting event. In a sample of 41 male supporters of a rugby team, all of whom had played the sport themselves, cardiovascular levels and psychological ratings of stress and anxiety were measured pre- and post-match. Counterfactual thinking was also assessed. Mixed factorial ANOVA analyses showed that in supporters who had recently retired from playing, psychological ratings of stress and anxiety were significantly lower pre-match compared to those who had long-retired (all ps < 0.001). However, significant phase × player status interactions identified that systolic blood pressure, F(1, 39) = 13.93, p = .001, partial ƞ2 = 0.26, diastolic blood pressure, F(1,39) = 24.62, p < .001, partial η2 = 39, and heart rate, F(1, 39) = 23.02, p < .001, partial η2 = 0.37, increased significantly in recent-retired players compared to long-retired players, indicating that they found watching the match more stressful than the long-retired players. Furthermore, this effect was moderated by counterfactual thinking in recent-retired players only, where greater levels of counterfactual thinking was associated with greater cardiovascular reactivity. These findings confirm that watching a sporting fixture induces cardiovascular reactivity in spectators who recently retired from the sport, with counterfactual thinking a possible underlying pathway.

Metabolic syndrome in polycystic ovary syndrome: a systematic review, meta-analysis and meta-regression.

INTRODUCTION: Women with polycystic ovary syndrome (PCOS) have increased risk of metabolic syndrome. The relative contribution of clinical, demographic or biochemical factors to metabolic syndrome in PCOS is not known. A literature search was conducted in MEDLINE, CINAHL, EMBASE and clinical trial registries. Of 4530 studies reviewed, 59 were included in the systematic review and 27 in the meta-analysis and meta-regression. In good and fair quality studies, women with PCOS had an overall increased prevalence of metabolic syndrome (odds ratio, OR 3.35, 95% confidence interval, CI 2.44, 4.59). Increased prevalence of metabolic syndrome occurred in overweight or obese women with PCOS (OR 1.88, 95% 1.16, 3.04) but not in lean women (OR 1.45, 95% CI 0.35, 6.12). In meta-regression analyses, the markers of metabolic syndrome diagnostic criteria (waist circumference, high-density lipoprotein cholesterol, triglyceride, blood pressure), BMI, glucose tolerance (2-hr oral glucose tolerance test) and surrogate markers of insulin resistance (HOMA-IR) but not markers of reproductive dysfunction (sex hormone binding globulin, testosterone, PCOS phenotypes) contributed significantly to the heterogeneity in the prevalence of metabolic syndrome. Women with PCOS have increased risk of metabolic syndrome which was associated with obesity and metabolic features but not with indices of hyperandrogenism.

Giant Cell Arteritis Presenting as an Ischaemic Upper Limb

Aim To present an interesting case of giant cell arteritis presenting as ischaemic upper limb. Methods Data was collected from the patient's chart and from radiology and laboratory systems in our institution. Results The patient had a temporal artery biopsy confirming the diagnosis of temporal arteritis. This was successfully treated with high dose steroids leading to resolution of symptoms in the arm. Conclusion Arteritis is an important consideration to consider in patients who present with limb ischaemia as it is a reversible cause which can be treated effectively.

Association of Early Outpatient Rehabilitation With Health Service Utilization in Managing Medicare Beneficiaries With Nontraumatic Knee Pain: Retrospective Cohort Study.

BACKGROUND: Nontraumatic knee pain (NTKP) is highly prevalent in adults 65 years of age and older. Evidence-based guidelines recommend early use of rehabilitation; however, there is limited information comparing differences in health care utilization when rehabilitation is included in the management of NTKP. OBJECTIVES: To describe the overall health care utilization associated with the management of NTKP; estimate the proportion of people who receive outpatient rehabilitation services; and evaluate the timing of outpatient rehabilitation and its association with other health care utilization. DESIGN: Rretrospective cohort study was conducted using a random 10% sample of 2009-2010 Medicare claims. The sample included 52,504 beneficiaries presenting within the ambulatory setting for management of NTKP. METHODS: Exposure to outpatient rehabilitative services following the NTKP index ambulatory visit was defined as 1) no rehabilitation; 2) early rehabilitation (1-15 days); 3) intermediate rehabilitation (16-120 days); and 4) late rehabilitation (>120 days). Logistic regression models were fit to analyze the association of rehabilitation timing with narcotic analgesic use, utilization of nonsurgical invasive procedure, and knee surgery during a 12-month follow-up period. RESULTS: Only 11.1% of beneficiaries were exposed to outpatient rehabilitation services. The likelihood of using narcotics, nonsurgical invasive procedures, or surgery was significantly less (adjusted odds ratios; 0.67, 0.50, 0.58, respectively) for those who received early rehabilitation when compared to no rehabilitation. The exposure-outcome relationships were reversed in the intermediate and late rehabilitation cohorts. LIMITATIONS: This was an observational study, and residual confounding could affect the observed relationships. Therefore, definitive conclusions regarding the causal effect of rehabilitation exposure and reduced utilization of more aggressive interventions cannot be determined at this time. CONCLUSIONS: Early referral for outpatient rehabilitation may reduce the utilization of health services that carry greater risks or costs in those with NTKP.

The ability of preoperative factors to predict patient-reported disability following surgery for rotator cuff pathology.

PURPOSE: Minimal research has examined the prognostic ability of shoulder examination data or psychosocial factors in predicting patient-reported disability following surgery for rotator cuff pathology. The purpose of this study was to examine these factors for prognostic value in order to help clinicians and patients understand preoperative factors that impact disability following surgery. METHODS: Sixty-two patients scheduled for subacromial decompression with or without supraspinatus repair were recruited. Six-month follow-up data were available for 46 patients. Patient characteristics, history of the condition, shoulder impairments, psychosocial factors, and patient-reported disability questionnaires were collected preoperatively. Six months following surgery, the Western Ontario Rotator Cuff Index (WORC) and global rating of change dichotomized subjects into responders versus nonresponders. Logistic regression quantified prognostic ability and created the most parsimonious model to predict outcome. RESULTS: Being on modified job duty (OR = .17, 95%CI: 0.03-0.94), and having a worker's compensation claim (OR = 0.08, 95%CI: 0.01-0.74) decreased probability of a positive outcome, while surgery on the dominant shoulder (OR = 11.96, 95%CI: 2.91-49.18) increased probability. From the examination, only impaired internal rotation strength was a significant univariate predictor. The Fear-avoidance Beliefs Questionnaire (FABQ) score (OR = 0.95, 95%CI: 0.91-0.98) and the FABQ_work subscale (OR = 0.92, 95%CI: 0.87-0.97) were univariate predictors. In the final model, surgery on the dominant shoulder (OR = 8.9, 95%CI 1.75-45.7) and FABQ_work subscale score ≤25 (OR = 15.3, 95%CI 2.3-101.9) remained significant. DISCUSSION: Surgery on the dominant arm resulted in greater improvement in patient-reported disability, thereby increasing the odds of a successful surgery. The predictive ability of the FABQ_work subscale highlights the potential impact of psychosocial factors on patient-reported disability. Implications for Rehabilitation Impairment-based shoulder measurements were not strong predictors of patient-reported outcome. Having high fear-avoidance behavior scores on the FABQ, especially the work subscale, resulted in a much lower chance of responding well to rotator cuff surgery as measured by self-reported disability. Having surgery on the dominant shoulder, as compared to the nondominant side, resulted in larger improvements in disability levels.

Influence of GABA and GABA-producing Lactobacillus brevis DPC 6108 on the development of diabetes in a streptozotocin rat model.

The aim of this study was to investigate if dietary administration of γ-aminobutyric acid (GABA)-producing Lactobacillus brevis DPC 6108 and pure GABA exert protective effects against the development of diabetes in streptozotocin (STZ)-induced diabetic Sprague Dawley rats. In a first experiment, healthy rats were divided in 3 groups (n=10/group) receiving placebo, 2.6 mg/kg body weight (bw) pure GABA or L. brevis DPC 6108 (~10(9)microorganisms). In a second experiment, rats (n=15/group) were randomised to five groups and four of these received an injection of STZ to induce type 1 diabetes. Diabetic and non-diabetic controls received placebo [4% (w/v) yeast extract in dH2O], while the other three diabetic groups received one of the following dietary supplements: 2.6 mg/kg bw GABA (low GABA), 200 mg/kg bw GABA (high GABA) or ~10(9) L. brevis DPC 6108. L. brevis DPC 6108 supplementation was associated with increased serum insulin levels (P<0.05), but did not alter other metabolic markers in healthy rats. Diabetes induced by STZ injection decreased body weight (P<0.05), increased intestinal length (P<0.05) and stimulated water and food intake. Insulin was decreased (P<0.05), whereas glucose was increased (P<0.001) in all diabetic groups, compared with non-diabetic controls. A decrease (P<0.01) in glucose levels was observed in diabetic rats receiving L. brevis DPC 6108, compared with diabetic-controls. Both the composition and diversity of the intestinal microbiota were affected by diabetes. Microbial diversity in diabetic rats supplemented with low GABA was not reduced (P>0.05), compared with non-diabetic controls while all other diabetic groups displayed reduced diversity (P<0.05). L. brevis DPC 6108 attenuated hyperglycaemia induced by diabetes but additional studies are needed to understand the mechanisms involved in this reduction.

Neuromuscular electrical stimulation as a method to maximize the beneficial effects of muscle stem cells transplanted into dystrophic skeletal muscle.

Cellular therapy is a potential approach to improve the regenerative capacity of damaged or diseased skeletal muscle. However, its clinical use has often been limited by impaired donor cell survival, proliferation and differentiation following transplantation. Additionally, functional improvements after transplantation are all-too-often negligible. Because the host microenvironment plays an important role in the fate of transplanted cells, methods to modulate the microenvironment and guide donor cell behavior are warranted. The purpose of this study was to investigate whether the use of neuromuscular electrical stimulation (NMES) for 1 or 4 weeks following muscle-derived stem cell (MDSC) transplantation into dystrophic skeletal muscle can modulate the fate of donor cells and enhance their contribution to muscle regeneration and functional improvements. Animals submitted to 4 weeks of NMES after transplantation demonstrated a 2-fold increase in the number of dystrophin+ myofibers as compared to control transplanted muscles. These findings were concomitant with an increased vascularity in the MDSC+NMES group when compared to non-stimulated counterparts. Additionally, animals subjected to NMES (with or without MDSC transplantation) presented an increased maximal specific tetanic force when compared to controls. Although cell transplantation and/or the use of NMES resulted in no changes in fatigue resistance, the combination of both MDSC transplantation and NMES resulted in a faster recovery from fatigue, when compared to non-injected and non-stimulated counterparts. We conclude that NMES is a viable method to improve MDSC engraftment, enhance dystrophic muscle strength, and, in combination with MDSC transplantation, improve recovery from fatigue. These findings suggest that NMES may be a clinically-relevant adjunct approach for cell transplantation into skeletal muscle.

Development and preliminary testing of the psychosocial adjustment to hereditary diseases scale.

BACKGROUND: The presence of Lynch syndrome (LS) can bring a lifetime of uncertainty to an entire family as members adjust to living with a high lifetime cancer risk. The research base on how individuals and families adjust to genetic-linked diseases following predictive genetic testing has increased our understanding of short-term impacts but gaps continue to exist in knowledge of important factors that facilitate or impede long-term adjustment. The failure of existing scales to detect psychosocial adjustment challenges in this population has led researchers to question the adequate sensitivity of these instruments. Furthermore, we have limited insight into the role of the family in promoting adjustment. METHODS: The purpose of this study was to develop and initially validate the Psychosocial Adjustment to Hereditary Diseases (PAHD) scale. This scale consists of two subscales, the Burden of Knowing (BK) and Family Connectedness (FC). Items for the two subscales were generated from a qualitative data base and tested in a sample of 243 participants from families with LS. RESULTS: The Multitrait/Multi-Item Analysis Program-Revised (MAP-R) was used to evaluate the psychometric properties of the PAHD. The findings support the convergent and discriminant validity of the subscales. Construct validity was confirmed by factor analysis and Cronbach's alpha supported a strong internal consistency for BK (0.83) and FC (0.84). CONCLUSION: Preliminary testing suggests that the PAHD is a psychometrically sound scale capable of assessing psychosocial adjustment. We conclude that the PAHD may be a valuable monitoring tool to identify individuals and families who may require therapeutic interventions.

Effect of assay specificity on the association of urine 11-dehydro thromboxane B2 determination with cardiovascular risk.

BACKGROUND: Elevated urine 11-dehydro TXB(2), an indicator of persistent thromboxane generation in aspirin-treated patients, correlates with adverse cardiovascular outcome and has recently been identified as an independent risk factor for vein graft thrombosis after cardiac bypass surgery in the Reduction in Graft Occlusion Rates (RIGOR) study. The polyclonal antibody-based ELISA used to measure 11-dehydro TXB(2) in these previous studies is no longer clinically available and has been supplanted by a Food and Drug Administration (FDA)-cleared second-generation monoclonal antibody-based ELISA. OBJECTIVES: To compare the laboratory and clinical performance of the first- and second-generation assays in a well-defined study population. METHODS: 11-dehydro TXB(2) was quantified in 451 urine samples from 229 Reduction in Graft Occlusion Rates (RIGOR) subjects using both ELISA. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and spiking studies were used to investigate discordant assay results. The association of 11-dehydro TXB(2) to clinical outcome was assessed for each assay using multivariate modeling. RESULTS: Median 11-dehydro TXB(2) levels were higher by monoclonal antibody- compared with polyclonal antibody-based ELISA (856 vs. 399 pg mg(-1) creatinine, P < 0.000001), with the latter providing values similar to UPLC-MS/MS. This discrepancy was predominantly as a result of cross-reactivity of the monoclonal antibody with 11-dehydro-2,3-dinor TXB(2), a thromboxane metabolite present in a similar concentration but with a poor direct correlation with 11-dehydro TXB(2). In contrast to the first-generation ELISA, 11-dehydro TXB(2) measured by the monoclonal antibody-based ELISA failed to associate with the risk of vein graft occlusion. CONCLUSION: Quantification of urine 11-dehydro TXB(2) by monoclonal antibody-based ELISA was confounded by interference from 11-dehydro-2,3-dinor TXB(2) which reduced the accuracy and clinical utility of this second-generation assay.

"In somno securitas" anaesthetists' noise exposure in Orthopaedic operating theatres.

Excessive noise exposure can have adverse effects on the health and performance of healthcare providers. Irish statutory regulations limit daily workplace noise exposure to 87 A-weighted decibels [dB(A)]. The World Health Organisation recommends noise levels remain under 35 dB(A) in patient treatment rooms. We measured anaesthetists' noise exposure during elective orthopaedic surgery. The mean and maximum sound levels were 63.0 (SD 4.26) and 92.8 dB(A) respectively. Noise was louder than 65 dB(A) 22.2% of the time and louder than 80 dB(A) less than 1% of the time. Staff conversation and metal instruments were responsible for 29.5% and 19.9% of peaks louder than 65 dB(A) respectively. Sound levels recorded were lower than recognised levels associated with hearing loss. Sound regularly exceeded World Health Organisation (WHO) recommended levels for patient comfort and safety. Anaesthetists need to be aware of the influence of environmental noise on clinical practice.

A murine model of muscle training by neuromuscular electrical stimulation.

Neuromuscular electrical stimulation (NMES) is a common clinical modality that is widely used to restore (1), maintain (2) or enhance (3-5) muscle functional capacity. Transcutaneous surface stimulation of skeletal muscle involves a current flow between a cathode and an anode, thereby inducing excitement of the motor unit and the surrounding muscle fibers. NMES is an attractive modality to evaluate skeletal muscle adaptive responses for several reasons. First, it provides a reproducible experimental model in which physiological adaptations, such as myofiber hypertophy and muscle strengthening (6), angiogenesis (7-9), growth factor secretion (9-11), and muscle precursor cell activation (12) are well documented. Such physiological responses may be carefully titrated using different parameters of stimulation (for Cochrane review, see (13)). In addition, NMES recruits motor units non-selectively, and in a spatially fixed and temporally synchronous manner (14), offering the advantage of exerting a treatment effect on all fibers, regardless of fiber type. Although there are specified contraindications to NMES in clinical populations, including peripheral venous disorders or malignancy, for example, NMES is safe and feasible, even for those who are ill and/or bedridden and for populations in which rigorous exercise may be challenging. Here, we demonstrate the protocol for adapting commercially available electrodes and performing a NMES protocol using a murine model. This animal model has the advantage of utilizing a clinically available device and providing instant feedback regarding positioning of the electrode to elicit the desired muscle contractile effect. For the purpose of this manuscript, we will describe the protocol for muscle stimulation of the anterior compartment muscles of a mouse hindlimb.

Modification of the technical properties of Lactobacillus johnsonii NCC 533 by supplementing the growth medium with unsaturated fatty acids.

The aim of this study was to investigate the influence of supplementing growth medium with unsaturated fatty acids on the technical properties of the probiotic strain Lactobacillus johnsonii NCC 533, such as heat and acid tolerance, and inhibition of Salmonella enterica serovar Typhimurium infection. Our results showed that the membrane composition and morphology of L. johnsonii NCC 533 were significantly changed by supplementing a minimal Lactobacillus medium with oleic, linoleic, and linolenic acids. The ratio of saturated to unsaturated plus cyclic fatty acids in the bacterial membrane decreased by almost 2-fold when minimal medium was supplemented with unsaturated fatty acids (10 µg/ml). The subsequent acid and heat tolerance of L. johnsonii decreased by 6- and 20-fold when the strain was grown in the presence of linoleic and linolenic acids, respectively, compared with growth in oleic acid (all at 10 µg/ml). Following acid exposure, significantly higher (P < 0.05) oleic acid content was detected in the membrane when growth medium was supplemented with linoleic or linolenic acid, indicating that saturation of the membrane fatty acids occurred during acid stress. Cell integrity was determined in real time during stressed conditions using a fluorescent viability kit in combination with flow cytometric analysis. Following heat shock (at 62.5°C for 5 min), L. johnsonii was unable to form colonies; however, 60% of the bacteria showed no cell integrity loss, which could indicate that the elevated heat inactivated vital processes within the cell, rendering it incapable of replication. Furthermore, L. johnsonii grown in fatty acid-enriched minimal medium had different adhesion properties and caused a 2-fold decrease in S. enterica serovar Typhimurium UK1-lux invasion of HT-29 epithelial cells compared with bacteria grown in minimal medium alone. This could be related to changes in the hydrophobicity and fluidity of the membrane. Our study shows that technical properties underlying probiotic survivability can be affected by nutrient composition of the growth medium.

Metabolic activities and probiotic potential of bifidobacteria.

It has been shown that the gut microbiota regulates fat storage in the body and that disturbances in its composition can lead to the development of certain metabolic disease states. Bifidobacteria are found among the resident microbiota in the gastrointestinal tract (GIT) and their metabolic activities have been shown to beneficially influence the human host. It has been reported that they inhibit intestinal colonisation by pathogenic microorganisms and have anti-carcinogenic, immunostimulatory, and anti-diarrhoeal properties, as well as aiding in the alleviation of lactose intolerance and ability to lower serum cholesterol levels in humans. One particular health promoting property of bifidobacteria is bioactive fatty acid production, which when ingested, may confer health benefits on the host. A bioactive fatty acid produced by bifidobacteria is conjugated linoleic acid (CLA), of which cis-9, trans-11 (c9, t11) and trans-10, cis-12 (t10, c12) CLA are the main biologically active CLA isomers. The production of CLA by Bifidobacterium can also have a positive effect on the immune system of the human host leading to numerous health benefits. This is an example of the metabolic activities of an ingested bacterium being beneficial to the host, rather than the direct interaction of the bacterium with the host.

Psychological health impact on 2-year changes in pain and function in persons with knee pain: data from the Osteoarthritis Initiative.

OBJECTIVE: We determined whether baseline depressive symptoms, knee-related confidence and general psychological distress influenced changes in pain and function during 2 years of follow-up. DESIGN: We included persons in the Osteoarthritis Initiative (OAI) dataset with baseline pain of 1 or greater on a 0-10 scale in at least one knee and no knee or hip surgery during the 2-year follow-up (n=3407). The four outcome variables were repeated chair standing, 20 m walk and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain and Disability. Linear mixed effects models assessed the association of each mental health variable with the yearly change in each baseline adjusted outcome measure after controlling for covariates. RESULTS: Depressive symptoms were significantly predictive of worsening in most outcomes. The magnitude of worsening predicted for each year was small. For example, the dichotomized WOMAC Pain model indicated that depressed persons experience more rapid worsening than non-depressed persons at an average rate of 0.59 WOMAC points per year (95% CI 0.176, 1.013, P=0.005). Similar significant but very small effects of depressive symptoms on other outcomes were observed. Knee confidence was not predictive of change. General psychological distress was predictive of change in 20-m walk and WOMAC Pain. CONCLUSIONS: The most consistent psychological predictor of yearly worsening was baseline depressive symptoms. Although a statistically robust predictor of outcome, given that change was very small and highly dependent on baseline status, our results indicate that a considerable degree of persistent depressive symptoms would be required to have a meaningful effect on future self-reported outcome.

A role for proline synthesis and transport in Listeria monocytogenes barotolerance.

AIMS: To assess the contribution of proline biosynthesis to listerial barotolerance. METHODS AND RESULTS: Using a Listeria monocytogenes proBA deletion mutant, incapable of synthesizing proline, together with a proline-overproducing strain, the contribution of proline synthesis to listerial barotolerance was determined. The ΔproBA strain does not survive as well as the wild type when subjected to treatment of 500 MPa in rich media and 400 MPa in minimal media (c. 1 log lower survival in both conditions). Betaine and carnitine decrease the ability of the wild type to survive at low pressures (300 MPa), but confer normal or slightly increased levels of protection at higher pressures (350 and 400 MPa). CONCLUSIONS: A functional proline synthesis system is required for optimal survival of Listeria following treatment at high-pressure (HP) levels (500 MPa in brain heart infusion and 400 MPa in defined medium), particularly where other compatible solutes are absent or limiting. SIGNIFICANCE AND IMPACT OF THE STUDY: Given the potential of HP processing as an effective food processing/safety strategy, understanding how pathogens such as Listeria have evolved to cope with such stresses is an important food safety consideration. In this context, the work presented here may help to develop safer and more effective processing regimens.

Novel listerial genetic loci conferring enhanced barotolerance in Escherichia coli.

AIMS: To identify Listeria monocytogenes genes with a role in high-pressure (HP) resistance. METHODS AND RESULTS: A L. monocytogenes genomic library constructed in an Escherichia coli background was screened for loci conferring increased HP resistance. Pressure treatments at 400 megapascals for 5 min in Luria-Bertani (LB) agar were used to screen for increased resistance to pressure. Colonies arising on the treated agar plates were isolated, the plasmid extracted and the inserts sequenced to identify the genetic loci conferring HP resistance. Seven different genetic regions were identified, which encoded proteins similar to an inorganic polyphosphate/ATP-NAD kinase, the septation ring formation regulator EzrA, flagellar motor proteins MotA and MotB, proteins similar to the quorum sensing Agr system from Staphylococcus (AgrA, AgrC and AgrD), proteins similar to a transcription regulator (RpiR family) and a fructose phosphotransferase system, proteins of unknown function, and a Fur regulator. Of the seven loci confirmed, three (EzrA, MotA/B and the Agr system) maintained significantly reproducible HP tolerance when expressed in a different E. coli background. CONCLUSIONS: Novel genetic loci from the L. monocytogenes genome confer increased HP resistance when heterologously expressed in an E. coli background. SIGNIFICANCE AND IMPACT OF THE STUDY: Molecular and functional approaches to the screening of genetic elements linked to HP resistance provide greater insights into microbial inactivation and/or survival mechanisms when using HP as a means of controlling/eliminating bacterial growth. This information will ultimately have significant implications for the use of HP processing in the food industry, in terms of both food quality and safety.