Where next for the design, delivery, and evaluation of community-based physical activity prescription? Emerging lessons from the United Kingdom.

Despite widespread use, community-based physical activity prescription is controversial. Data limitations have resulted in a lack of clarity about what works, under what circumstances, and for whom, reflected in conservative policy recommendations. In this commentary we challenge a predominantly negative discourse, using contemporary research to highlight promising findings and "lessons learnt" for design, delivery, and evaluation. In doing so, we argue for the importance of a more nuanced approach to future commissioning and evaluation. Novelty: Amalgamating learning from multiple research teams to create recommendations for advancing physical activity prescription.

Dissecting the Role of VicK Phosphatase in Aggregation and Biofilm Formation of Streptococcus mutans.

VicRK (WalRK or YycFG) is a conserved 2-component regulatory system (TCS) that regulates cell division, cell wall biosynthesis, and homeostasis in low-GC Gram-positive bacteria. VicRK is also associated with biofilm formation of Streptococcus mutans on the tooth surface as it directly regulates the extracellular polysaccharide (EPS) synthesis. Of the 2 components, VicK possesses both autokinase and phosphatase activities, which regulate the phosphorylation and dephosphorylation of the regulator VicR in response to environmental cues. However, the dual mechanism of VicK as the autokinase/phosphatase in regulating S. mutans' responses is not well elucidated. Previously, it has been shown that the phosphatase activity depends on the PAS domain and residues in the DHp domain of VicK in S. mutans. Specifically, mutating proline at 222 in the PAS domain inhibits VicK phosphatase activity. We generated a VicKP222A mutant to determine the level of VicR-P in the cytoplasm by Phos-tag sodium dodecyl sulfate polyacrylamide gel electrophoresis. We show that in VicKP222A phosphatase, attenuation increased phosphorylated VicR (VicR-P) that downregulated glucosyltransferases, gtfBC, thereby reducing the synthesis of water-insoluble polysaccharides (WIS-EPS) in the biofilm. In addition, VicKP222A presented as long-rod cells, reduced growth, and displayed asymmetrical division. A major adhesin of S. mutans, SpaP was downregulated in VicKP222A, making it unable to agglutinate in saliva. In summary, we have confirmed that VicK phosphatase activity is critical to maintain optimal phosphorylation status of VicR in S. mutans, which is important for cell growth, cell division, EPS synthesis, and bacterial agglutination in saliva. Hence, VicK phosphatase activity may represent a promising target to modulate S. mutans' pathogenicity.

Novel method for the depletion of cariogenic bacteria using dextranomer microspheres.

Streptococcus mutans is recognized as one of the key contributors to the dysbiotic state that results in dental caries. Existing treatment strategies reduce the incidence of tooth decay, but they also eliminate both the cariogenic and beneficial microbes. Here we introduce a novel treatment alternative using Sephadex, cross-linked dextranomer microspheres (DMs), typically used for gel filtration chromatography. In addition DM beads can be used for affinity purification of glucosyltransferases (GTFs) from S. mutans. In this study we take advantage of the native pathogenic mechanisms used by S. mutans to adhere, form a biofilm and induce dental caries through the expression of surface-associated GTFs. We demonstrate that planktonic and biofilm-grown (adhered to hydroxyapatite-coated pegs to mimic the tooth surface) S. mutans, specifically and competitively attach to DMs. Further investigation demonstrated that DMs are a specific affinity resin for S. mutans and other cariogenic/pathogenic oral streptococci, whereas other commensal and probiotic strains failed to readily adhere to DMs. Using antimicrobial cargo loaded into the DM lumen, we demonstrate that when in co-culture with non-binding to even modestly binding commensal species, S. mutans was selectively killed. This proof of concept study introduces a novel means to safely and effectively reduce the pool of S. mutans and other pathogenic streptococci in the oral cavity with limited disturbance of the necessary commensal (healthy) microbiota when compared with current oral healthcare products.

Intestinal helminth infection impacts the systemic distribution and function of the naive lymphocyte pool.

Homeostasis is a fundamental principle of biological systems. A paradigm of immune homeostasis is the remarkably constant number of naive T and B lymphocytes in the body that continuously circulate through the secondary lymphoid organs to maximize immune surveillance. Whether the dynamics and distribution of the systemic naive lymphocyte pool is affected following organ-specific infection is not known. Here we show that, following infection of mice with an enteric helminth, naive T and B lymphocytes accumulate in the T helper type 2-reactive mesenteric lymph node while they are concurrently depleted from non-draining peripheral lymph nodes. This systemic redistribution of naive lymphocytes is sustained into the chronic phase of the infection, requires lymphotoxin beta receptor-dependent signals and is associated with a reduced ability of parasitized animals to mount antigen-specific cellular and humoral immune responses to heterologous immunization or infection at peripheral sites. Our data suggest that the function of the homeostatic naive lymphocyte pool can be modulated by its systemic distribution following infection and may provide a novel concept underlying compromised immune responsiveness at peripheral sites in helminth-infected individuals.

A bacterial-biofilm-induced oral osteolytic infection can be successfully treated by immuno-targeting an extracellular nucleoid-associated protein.

Periodontal disease exemplifies a chronic and recurrent infection with a necessary biofilm component. Mucosal inflammation is a hallmark response of the host seen in chronic diseases, such as colitis, gingivitis, and periodontitis (and the related disorder peri-implantitis). We have taken advantage of our recently developed rat model of human peri-implantitis that recapitulates osteolysis, the requirement of biofilm formation, and the perpetuation of the bona fide disease state, to test a new therapeutic modality with two novel components. First we used hyperimmune antiserum directed against the DNABII family of proteins, now known to be a critical component of the extracellular matrix of bacterial biofilms. Second we delivered the antiserum as cargo in biodegradable microspheres to the site of the biofilm infection. We demonstrated that delivery of a single dose of anti-DNABII in poly(lactic-co-glycolic acid) (PLGA) microspheres induced significant resolution of experimental peri-implantitis, including marked reduction of inflammation. These data support the continued development of a DNABII protein-targeted therapeutic for peri-implantitis and other chronic inflammatory pathologies of the oral cavity in animals and humans.

9th Hatter Biannual Meeting: position document on ischaemia/reperfusion injury, conditioning and the ten commandments of cardioprotection.

In the 30 years since the original description of ischaemic preconditioning, understanding of the pathophysiology of ischaemia/reperfusion injury and concepts of cardioprotection have been revolutionised. In the same period of time, management of patients with coronary artery disease has also been transformed: coronary artery and valve surgery are now deemed routine with generally excellent outcomes, and the management of acute coronary syndromes has seen decade on decade reductions in cardiovascular mortality. Nonetheless, despite these improvements, cardiovascular disease and ischaemic heart disease in particular, remain the leading cause of death and a significant cause of long-term morbidity (with a concomitant increase in the incidence of heart failure) worldwide. The need for effective cardioprotective strategies has never been so pressing. However, despite unequivocal evidence of the existence of ischaemia/reperfusion in animal models providing a robust rationale for study in man, recent phase 3 clinical trials studying a variety of cardioprotective strategies in cardiac surgery and acute ST-elevation myocardial infarction have provided mixed results. The investigators meeting at the Hatter Cardiovascular Institute workshop describe the challenge of translating strong pre-clinical data into effective clinical intervention strategies in patients in whom effective medical therapy is already altering the pathophysiology of ischaemia/reperfusion injury-and lay out a clearly defined framework for future basic and clinical research to improve the chances of successful translation of strong pre-clinical interventions in man.

Ten-dimensional anthropomorphic arm control in a human brain-machine interface: difficulties, solutions, and limitations.

OBJECTIVE: In a previous study we demonstrated continuous translation, orientation and one-dimensional grasping control of a prosthetic limb (seven degrees of freedom) by a human subject with tetraplegia using a brain-machine interface (BMI). The current study, in the same subject, immediately followed the previous work and expanded the scope of the control signal by also extracting hand-shape commands from the two 96-channel intracortical electrode arrays implanted in the subject's left motor cortex. APPROACH: Four new control signals, dictating prosthetic hand shape, replaced the one-dimensional grasping in the previous study, allowing the subject to control the prosthetic limb with ten degrees of freedom (three-dimensional (3D) translation, 3D orientation, four-dimensional hand shaping) simultaneously. MAIN RESULTS: Robust neural tuning to hand shaping was found, leading to ten-dimensional (10D) performance well above chance levels in all tests. Neural unit preferred directions were broadly distributed through the 10D space, with the majority of units significantly tuned to all ten dimensions, instead of being restricted to isolated domains (e.g. translation, orientation or hand shape). The addition of hand shaping emphasized object-interaction behavior. A fundamental component of BMIs is the calibration used to associate neural activity to intended movement. We found that the presence of an object during calibration enhanced successful shaping of the prosthetic hand as it closed around the object during grasping. SIGNIFICANCE: Our results show that individual motor cortical neurons encode many parameters of movement, that object interaction is an important factor when extracting these signals, and that high-dimensional operation of prosthetic devices can be achieved with simple decoding algorithms. ClinicalTrials.gov Identifier: NCT01364480.

Baroreceptor sensitivity after Valsalva maneuver in women with chronic obstructive pulmonary disease.

PURPOSE: Reduced baroreceptor sensitivity (BRS) results in changes in autonomic modulation. Patients with chronic obstructive pulmonary disease (COPD) may have altered BRS. Therefore, we compared BRS between COPD patients and normal controls. METHODS: We compared 14 COPD patients [mean (±SD) age, 62 ± 8 years] to 14 healthy controls [mean (±SD) age, 59 ± 6 years] for the loss of BRS. All patients received ß(2)-agonist therapy but were free from any other type of medication that would interfere with autonomic responses, all controls were free from cardiopulmonary disease, and none was taking medications. All participants were female, post-menopausal, had no known cardiac disease and were ex-smokers. Reduced baroreceptor sensitivity was determined using the slope of the magnitude of R-R widening over the increase in systolic blood pressure following Valsalva maneuver. RESULTS: The mean BRS in controls versus COPD patients showed a mean value of 6.15 ± 2.26 versus 1.91 ± 2.92 ms/mmHg (p < 0.001). CONCLUSIONS: These findings are consistent with other abnormalities of autonomic disruption as previously reported, and demonstrate a severe blunting of the baroreceptor response in individuals with COPD. The cause of this altered BRS response in COPD is not fully clear, we postulate that air trapping with persistent elevation of intrathoracic pressure may lead to a subsequent blunting of the sensitivity of the baroreceptors.

Regulation of bacteriocin production and cell death by the VicRK signaling system in Streptococcus mutans.

The VicRK two-component signaling system modulates biofilm formation, genetic competence, and stress tolerance in Streptococcus mutans. We show here that the VicRK modulates bacteriocin production and cell viability, in part by direct modulation of competence-stimulating peptide (CSP) production in S. mutans. Global transcriptome and real-time transcriptional analysis of the VicK-deficient mutant (SmuvicK) revealed significant modulation of several bacteriocin-related loci, including nlmAB, nlmC, and nlmD (P < 0.001), suggesting a role for the VicRK in producing mutacins IV, V, and VI. Bacteriocin overlay assays revealed an altered ability of the vic mutants to kill related species. Since a well-conserved VicR binding site (TGTWAH-N(5)-TGTWAH) was identified within the comC coding region, we confirmed VicR binding to this sequence using DNA footprinting. Overexpression of the vic operon caused growth-phase-dependent repression of comC, comDE, and comX. In the vic mutants, transcription of nlmC/cipB encoding mutacin V, previously linked to CSP-dependent cell lysis, as well as expression of its putative immunity factor encoded by immB, were significantly affected relative to the wild type (P < 0.05). In contrast to previous reports that proposed a hyper-resistant phenotype for the VicK mutant in cell viability, the release of extracellular genomic DNA was significantly enhanced in SmuvicK (P < 0.05), likely as a result of increased autolysis compared with the parent. The drastic influence of VicRK on cell viability was also demonstrated using vic mutant biofilms. Taken together, we have identified a novel regulatory link between the VicRK and ComDE systems to modulate bacteriocin production and cell viability of S. mutans.

Biofilms can be dispersed by focusing the immune system on a common family of bacterial nucleoid-associated proteins.

Bacteria that cause chronic and/or recurrent diseases often rely on a biofilm lifestyle. The foundation of the biofilm structure is the extracellular polymeric substance (EPS) that acts as a barrier to both effectors of the immune system and antimicrobial agents. Recent work has highlighted extracellular DNA (eDNA) as a key component common to many pathogenic biofilms. Here, we show that the DNABII family of proteins, well known for their strong structural influences on intracellular DNA, was also critical for the integrity of the EPS matrix of biofilms that contain eDNA. In fact, antisera derived against a purified Escherichia coli DNABII family member rapidly disrupts the biofilm EPS formed by multiple human pathogens in vitro. In addition, when a member of this family of proteins was used as an immunogen in an animal model in which the bacteria had already formed a robust biofilm at the site of infection, the resultant targeted immune response strongly ameliorated this biofilm disease in vivo. Finally, this methodology to debulk the biofilm of EPS was shown to work synergistically with otherwise ineffective traditional anti-microbial approaches in vitro. We discuss the prospects for targeting DNABII family members as a potential universal strategy for treating biofilm diseases.

Drosophila male courtship behavior is modulated by ecdysteroids.

Temperature-dependent induction of ecdysteroid deficiency in the ecdysoneless mutant ecd(1) adult Drosophila melanogaster results in altered courtship behavior in males. Ecdysteroid deficiency brings about significantly elevated male-male courtship behavior including song production resembling that directed toward females. Supplementation with dietary 20-hydroxyecdysone reduces male-male attraction, but does not change motor activity, courtship patterns or attraction to females. These observations support the hypothesis that reduced levels of ecdysteroids increase the probability that male fruit flies will display courtship behaviors to male stimuli.

Epidemiology of influenza-associated hospitalization in adults, Toronto, 2007/8.

The purpose of this investigation was to identify when diagnostic testing and empirical antiviral therapy should be considered for adult patients requiring hospitalization during influenza seasons. During the 2007/8 influenza season, six acute care hospitals in the Greater Toronto Area participated in active surveillance for laboratory-confirmed influenza requiring hospitalization. Nasopharyngeal (NP) swabs were obtained from patients presenting with acute respiratory or cardiac illness, or with febrile illness without clear non-respiratory etiology. Predictors of influenza were analyzed by multivariable logistic regression analysis and likelihoods of influenza infection in various patient groups were calculated. Two hundred and eighty of 3,917 patients were found to have influenza. Thirty-five percent of patients with influenza presented with a triage temperature >or=38.0 degrees C, 80% had respiratory symptoms in the emergency department, and 76% were >or=65 years old. Multivariable analysis revealed a triage temperature >or=38.0 degrees C (odds ratio [OR] 3.1; 95% confidence interval [CI] 2.3-4.1), the presence of respiratory symptoms (OR 1.7; 95% CI 1.2-2.4), admission diagnosis of respiratory infection (OR 1.8; 95% CI 1.3-2.4), admission diagnosis of exacerbation of chronic obstructive pulmonary disease (COPD)/asthma or respiratory failure (OR 2.3; 95% CI 1.6-3.4), and admission in peak influenza weeks (OR 4.2; 95% CI 3.1-5.7) as independent predictors of influenza. The likelihood of influenza exceeded 15% in patients with respiratory infection or exacerbation of COPD/asthma if the triage temperature was >or=38.0 degrees C or if they were admitted in the peak weeks during the influenza season. During influenza season, diagnostic testing and empiric antiviral therapy should be considered in patients requiring hospitalization if respiratory infection or exacerbation of COPD/asthma are suspected and if either the triage temperature is >or=38.0 degrees C or admission is during the weeks of peak influenza activity.

Dectin-1 and inflammation-associated gene transcription and expression in mouse lungs by a toxic (1,3)-beta-D glucan.

The form of (1-3)-beta-D glucan found in the cell walls of the anamorphic Trichocomaceae that grow on damp building materials is considered to have potent toxic and inflammatory effects on cells of the respiratory system. It is also considered to have a potential role in the development of non-allergenic respiratory health effects. While human studies involving experimental exposures all point to the inflammatory potential of pure curdlan, a linear (1-3)-beta-D glucan in a triple helix configuration, animal experiments result in conflicting conclusions concerning the inflammatory potency of this glucan. However, because mice appear to be a better model than guinea pigs for exploring the respiratory effects of curdlan and because molecular mechanisms associated with this glucan remain largely unknown, we conducted further work to clarify the role of curdlan on the inflammatory response using our mouse model of lung disease. This study used in situ hybridization (ISH) to probe dectin-1 mRNA transcription with a digoxigenin-labeled cDNA probe, with reverse transcription (RT)-PCR based arrays used to measure inflammation gene and receptor transcriptional responses. Also, immunohistochemistry (IHC) was used to probe dectin-1 as well as anti-mouse Ccl3, Il1-alpha, and TNF-alpha expression to evaluate dose and time-course (4 and 12 h) postexposure (PE) response patterns in the lungs of intratracheally instilled mice exposed to a single 50 mul dose of curdlan at 10(-7), 10(-8), 10(-9), and 10(-10) M/animal (=4 mug to 4 ng curdlan/kg lung wt). Dectin-1 mRNA transcription and expression was observed in bronchiolar epithelium, alveolar macrophages (AMs), and alveolar type II cells (ATIIs) of lungs exposed to 4 mug to 40 ng curdlan/kg lung wt, at both time points. Compared to controls, array analysis revealed that 54 of 83 genes assayed were significantly modulated by curdlan. mRNA transcription patterns showed both dose and time dependency, with highest transcription levels in 10(-7) and 10(-8) M treatment animals, especially at 4-h PE. Nine gene mRNA transcripts (Ccl3, Ccl11, Ccl17, Ifng, Il1alpha, Il-20, TNF-alpha, Tnfrsf1b, and CD40lg) were significantly expressed at all doses suggesting they may have a central role in immunomodulating curdlan exposures. IHC revealed Ccl3, Il1-alpha, and TNF-alpha expression in bronchiolar epithelium, AMs and ATIIs illustrate the important immunomodulatory role that these cells have in the recognition of, and response to glucan. Collectively, these results confirm the inflammatory nature of curdlan and demonstrate the complex of inflammation-associated gene responses induced by (1-3)-beta-D glucan in triple helical forms. These observations also provide a biological basis for the irritant and inflammatory response to curdlan observed in humans and animals in experimental studies.

Protecting the acutely ischemic myocardium beyond reperfusion therapies: are we any closer to realizing the dream of infarct size elimination?

Patients currently treated for acute myocardial infarction receive reperfusion therapy as their only anti-infarct intervention. Although pharmacologic agents have been evaluated in the past for their ability to salvage ischemic myocardium when administered at reperfusion, until very recently none has demonstrated clear efficacy in clinical trials. However, a new generation of interventions has emerged which protects the heart by activating the reperfusion-induced salvage kinase (RISK) pathway. Unlike the disappointing results documented with previously touted putative cardioprotective agents, the preclinical experience with these newer interventions is very consistent indicating that there is a high likelihood that they will be effective clinically. Ischemic postconditioning, which also acts by activating the RISK pathway, has shown marked reduction in infarct size in small-scale trials. Finally, if a strategy for rapidly cooling the heart can be devised so that the in-hospital normothermic ischemic time can be significantly reduced, then infarct size can be even further decreased. In our opinion it is well within our reach using existing technologies to see the day when infarction can be virtually eliminated in the patient with acute coronary occlusion.

Cardioprotection: spotlight on PKG.

Classical ischaemic preconditioning, delayed or second window preconditioning and postconditioning are forms of cardioprotection that are dependent on cell surface receptors, intracellular signalling molecules and kinases that ultimately block formation of the mitochondrial permeability transition. The latter is presumed to cause myocardial necrosis as well as apoptosis, so prevention of its formation upon resumption of perfusion after a prolonged coronary occlusion should be cardioprotective. In all of these forms of cardioprotection, formation of cGMP and activation of protein kinase G (PKG) are recognized to be key steps in the signal transduction pathway. Burley et al. highlight the roles of cGMP and PKG in their comprehensive review. They describe the basic biology of PKG and emphasize its compartmentalization, which may be responsible for the frustration induced by assays for PKG in whole cell lysates and for the spurious conclusions about the role of PKG in cardioprotection. This review will be useful to both the novice and the seasoned investigator.

Economic analysis of unrelated allogeneic bone marrow transplantation: results from the randomized clinical trial of T-cell depletion vs unmanipulated grafts for the prevention of graft-versus-host disease.

Unrelated-donor marrow transplantation is a potential option for transplant candidates lacking a compatible related donor. The T-cell Depletion Study compared the 3-year disease-free survival for patients receiving T-cell-depleted (TCD) donor marrow (n = 203) vs unmanipulated donor marrow with methotrexate and cyclosporine (M/C) (n = 207). Hospital costs during index admission were documented with billing data, while hospital costs during subsequent 6-month follow-up were estimated from case report forms. Patients with index admission billing were included in the analysis (TCD = 119, M/C = 127). Total hospital length of stay (LOS) was similar across groups, with medians 47.0 days for TCD and 52.0 days for M/C (P = 0.72). Total hospital costs were comparable, 145,115 dollars vs 141,981 dollars (P = 0.63) for TCD and M/C, respectively. However, controlling for site and patient characteristics, TCD was associated with a 12.1% reduction in LOS for the index admission (95% CI -19.4%, -4.3%). Independent of treatment, HLA matching (6/6) was associated with an 8.6% (95% CI -17.4%, +1.2%) reduction in the index admission LOS, while cost was lower by 15.8% (95% CI -26.7%, -3.3%). Treatment costs were similar for TCD and M/C study groups. Savings on reduced cost for treating acute graft-versus-host disease were likely offset by increase in serious infections in the TCD arm.

The use of hand held mobile phones by drivers.

The use of mobile phones by drivers has been shown to be associated with an increased risk of motor vehicle crashes. The aim of this study was to identify the use of hand held mobiles phones by drivers in Ireland. Their use was investigated by a direct observation survey of drivers. The study showed that 3.6% of drivers were using hand held mobile phones while driving. This rate is high compared to other studies. Van drivers were three times more likely than other drivers to use a mobile phone whilst driving. Legislation needs to be introduced to ban their use and thereby reduce the risk of crashes.

The burden of alcohol misuse on emergency in-patient hospital admissions among residents from a health board region in Ireland.

AIMS: To identify in-patient emergency admissions to acute hospitals of residents from a health board region in the Republic of Ireland with an acute alcohol intoxication diagnosis; to profile the admissions and to assess whether the increase in alcohol consumption in Ireland has been mirrored by an increase in alcohol related emergency admissions over the same time period. DESIGN: A retrospective review of hospital admissions using Hospital In-Patient Enquiry (HIPE) data and alcohol consumption trends using data from the Central Statistics Office (CSO). SETTING: Acute hospitals in the Republic of Ireland. PARTICIPANTS: All residents from a health board region admitted with a recorded alcohol intoxication emergency admission to non-private acute hospitals in Ireland. MEASUREMENTS: All in-patient emergency admissions for which an acute alcohol intoxication diagnosis (ICD Codes 303.0 and 305.0) was recorded of residents from one health board region were extracted from the HIPE system for years 1997-2001 inclusive. Pearson's chi2 test was used to compare proportions in groups of categorical data and chi2 test for trend was used to identify linear trends. Age standardized rates were calculated for each year and trend analysis carried out. Demographic data on the patients were also extracted from the database. FINDINGS: There were 3289 acute alcohol intoxication admissions to acute hospitals of residents from the study region recorded for years 1997-2001 inclusive. There were 777 acute alcohol intoxication admissions in 2001 compared to 432 admissions in 1997, an increase of 80%. Age standardized rates showed a significant increasing linear trend (P < 0.001). Over half the admissions occurred on weekends. The average length of stay was 2.7 days (95% CI 2.5-2.8) with just under a quarter (24.3%) of these admissions being discharged on the same day. The majority of these patients were male (71.5%), 40.9% were under 30 years old and over half (59.4%) were single. CONCLUSIONS: This study shows that alcohol intoxication accounted for a substantial number of emergency in-patient admissions to acute hospitals in one health board region in Ireland and that the age standardized recorded acute alcohol related emergency admission rate increased significantly over the 5-year period, 1997-2001. This increase mirrored the national increase in alcohol consumption over the same time period.