Interventions to improve the appropriate use of polypharmacy for older people.

BACKGROUND: Inappropriate polypharmacy is a particular concern in older people and is associated with negative health outcomes. Choosing the best interventions to improve appropriate polypharmacy is a priority, so that many medicines may be used to achieve better clinical outcomes for patients. This is the third update of this Cochrane Review. OBJECTIVES: To assess the effects of interventions, alone or in combination, in improving the appropriate use of polypharmacy and reducing medication-related problems in older people. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, CINAHL and two trials registers up until 13 January 2021, together with handsearching of reference lists to identify additional studies. We ran updated searches in February 2023 and have added potentially eligible studies to 'Characteristics of studies awaiting classification'. SELECTION CRITERIA: For this update, we included randomised trials only. Eligible studies described interventions affecting prescribing aimed at improving appropriate polypharmacy (four or more medicines) in people aged 65 years and older, which used a validated tool to assess prescribing appropriateness. These tools can be classified as either implicit tools (judgement-based/based on expert professional judgement) or explicit tools (criterion-based, comprising lists of drugs to be avoided in older people). DATA COLLECTION AND ANALYSIS: Four review authors independently reviewed abstracts of eligible studies, and two authors extracted data and assessed the risk of bias of the included studies. We pooled study-specific estimates, and used a random-effects model to yield summary estimates of effect and 95% confidence intervals (CIs). We assessed the overall certainty of evidence for each outcome using the GRADE approach. MAIN RESULTS: We identified 38 studies, which includes an additional 10 in this update. The included studies consisted of 24 randomised trials and 14 cluster-randomised trials. Thirty-six studies examined complex, multi-faceted interventions of pharmaceutical care (i.e. the responsible provision of medicines to improve patients' outcomes), in a variety of settings. Interventions were delivered by healthcare professionals such as general physicians, pharmacists, nurses and geriatricians, and most were conducted in high-income countries. Assessments using the Cochrane risk of bias tool found that there was a high and/or unclear risk of bias across a number of domains. Based on the GRADE approach, the overall certainty of evidence for each pooled outcome ranged from low to very low. It is uncertain whether pharmaceutical care improves medication appropriateness (as measured by an implicit tool) (mean difference (MD) -5.66, 95% confidence interval (CI) -9.26 to -2.06; I2 = 97%; 8 studies, 947 participants; very low-certainty evidence). It is uncertain whether pharmaceutical care reduces the number of potentially inappropriate medications (PIMs) (standardised mean difference (SMD) -0.19, 95% CI -0.34 to -0.05; I2 = 67%; 9 studies, 2404 participants; very low-certainty evidence). It is uncertain whether pharmaceutical care reduces the proportion of patients with one or more PIM (risk ratio (RR) 0.81, 95% CI 0.68 to 0.98; I2 = 84%; 13 studies, 4534 participants; very low-certainty evidence). Pharmaceutical care may slightly reduce the number of potential prescribing omissions (PPOs) (SMD -0.48, 95% CI -1.05 to 0.09; I2 = 92%; 3 studies, 691 participants; low-certainty evidence), however it must be noted that this effect estimate is based on only three studies, which had serious limitations in terms of risk of bias. Likewise, it is uncertain whether pharmaceutical care reduces the proportion of patients with one or more PPO (RR 0.50, 95% CI 0.27 to 0.91; I2 = 95%; 7 studies, 2765 participants; very low-certainty evidence). Pharmaceutical care may make little or no difference to hospital admissions (data not pooled; 14 studies, 4797 participants; low-certainty evidence). Pharmaceutical care may make little or no difference to quality of life (data not pooled; 16 studies, 7458 participants; low-certainty evidence). Medication-related problems were reported in 10 studies (6740 participants) using different terms (e.g. adverse drug reactions, drug-drug interactions). No consistent intervention effect on medication-related problems was noted across studies. This also applied to studies examining adherence to medication (nine studies, 3848 participants). AUTHORS' CONCLUSIONS: It is unclear whether interventions to improve appropriate polypharmacy resulted in clinically significant improvement. Since the last update of this review in 2018, there appears to have been an increase in the number of studies seeking to address potential prescribing omissions and more interventions being delivered by multidisciplinary teams.

Structure-based pharmacophore modeling 1. Automated random pharmacophore model generation.

Pharmacophores are three-dimensional arrangements of molecular features required for biological activity that are often used in virtual screening efforts to prioritize ligands for experimental testing. G protein-coupled receptors (GPCR) are integral membrane proteins of considerable interest as targets for ligand discovery and drug development. Ligand-based pharmacophore models can be constructed to identify structural commonalities between known bioactive ligands for targets including GPCR. However, structure-based pharmacophores (which only require an experimentally determined or modeled structure for a protein target) have gained more attention to aid in virtual screening efforts as the number of publicly available experimentally determined GPCR structures have increased (140 unique GPCR represented as of October 24, 2022). Thus, the goal of this study was to develop a method of structure-based pharmacophore model generation applicable to ligand discovery for GPCR that have few known ligands. Pharmacophore models were generated within the active sites of 8 class A GPCR crystal structures via automated annotation of 5 randomly selected functional group fragments to sample diverse combinations of pharmacophore features. Each of the 5000 generated pharmacophores was then used to search a database containing active and decoy/inactive compounds for 30 class A GPCR and scored using enrichment factor and goodness-of-hit metrics to assess performance. Application of this method to the set of 8 class A GPCR produced pharmacophore models possessing the theoretical maximum enrichment factor value in both resolved structures (8 of 8 cases) and homology models (7 of 8 cases), indicating that generated pharmacophore models can prove useful in the context of virtual screening.

Benchmarking GPCR homology model template selection in combination with de novo loop generation.

G protein-coupled receptors (GPCR) comprise the largest family of membrane proteins and are of considerable interest as targets for drug development. However, many GPCR structures remain unsolved. To address the structural ambiguity of these receptors, computational tools such as homology modeling and loop modeling are often employed to generate predictive receptor structures. Here we combined both methods to benchmark a protocol incorporating homology modeling based on a locally selected template and extracellular loop modeling that additionally evaluates the presence of template ligands during these modeling steps. Ligands were also docked using three docking methods and two pose selection methods to elucidate an optimal ligand pose selection method. Results suggest that local template-based homology models followed by loop modeling produce more accurate and predictive receptor models than models produced without loop modeling, with decreases in average receptor and ligand RMSD of 0.54 Å and 2.91 Å, respectively. Ligand docking results showcased the ability of MOE induced fit docking to produce ligand poses with atom root-mean-square deviation (RMSD) values at least 0.20 Å lower (on average) than the other two methods benchmarked in this study. In addition, pose selection methods (software-based scoring, ligand complementation) selected lower RMSD poses with MOE induced fit docking than either of the other methods (averaging at least 1.57 Å lower), indicating that MOE induced fit docking is most suited for docking into GPCR homology models in our hands. In addition, target receptor models produced with a template ligand present throughout the modeling process most often produced target ligand poses with RMSD values ≤ 4.5 Å and Tanimoto coefficients > 0.6 after selection based on ligand complementation than target receptor models produced in the absence of template ligands. Overall, the findings produced by this study support the use of local template homology modeling in combination with de novo ECL2 modeling in the presence of a ligand from the template crystal structure to generate GPCR models intended to study ligand binding interactions.

Evaluation of different temporal periods between hormone-induced ovulation attempts in the female Fowler's toad Anaxyrus fowleri.

Many amphibian species reinitiate the processes of preparing for reproduction (e.g. oogenesis) soon after breeding indicating hormone-induced ovulation could potentially be achieved out-of-season, which would lead to higher annual fecundity compared to mono-seasonal breeding. Such strategies would be beneficial to captive breeding programs for threatened species that are short-lived, have aging populations or need large numbers of offspring to meet reintroduction goals for species recovery. Unfortunately, little is known regarding how female anurans respond to multiple ovulation events within a year, which could lead to higher annual fecundity compared to mono-seasonal breeding. Thus, we evaluated the effect of temporal period between exogenous hormone stimulation events on egg production using the Fowler's toad Anaxyrus fowleri as a model species. Female toads (n = 21) were administered hormone therapy twice in 1 year with toads randomly assigned to a treatment of either a 4-, 8- or 12-month recovery period between hormone stimulations. Ovulation was induced using two priming doses of human chorionic gonadotropin (100 IU; hCG) 72 h apart, followed by a resolving dose of hCG (500 IU) plus gonadotropin releasing hormone analogue (GnRHa; 15 µg) given 24 h after the second priming injection. Measured response variables include the number of females ovulating after treatment, total number of eggs produced and percent fertilization, neurula and tadpole development. No significant treatment effects were observed for any response variable (P > 0.05). Findings from this study suggest that hormone therapy can be administered in a bufonid species every 4 or 8 months without significantly affecting the number of ovulating females, egg production, fertilization, neurulation or tadpole development. By collecting gametes out-of-season or multiple times throughout the year, captive breeding programs could potentially increase tadpole production for reintroductions as well as extend the breeding window in captivity.

A benchmark study of loop modeling methods applied to G protein-coupled receptors.

G protein-coupled receptors (GPCR) are important drug discovery targets. Despite progress, many GPCR structures have not yet been solved. For these targets, comparative modeling is used in virtual ligand screening to prioritize experimental efforts. However, the structure of extracellular loop 2 (ECL2) is often poorly predicted. This is significant due to involvement of ECL2 in ligand binding for many Class A GPCR. Here we examine the performance of loop modeling protocols available in the Rosetta (cyclic coordinate descent [CCD], KIC with fragments [KICF] and next generation KIC [NGK]) and Molecular Operating Environment (MOE) software suites (de novo search). ECL2 from GPCR crystal structures served as the structure prediction targets and were divided into four sets depending on loop length. Results suggest that KICF and NGK sampled and scored more loop models with sub-angstrom and near-atomic accuracy than CCD or de novo search for loops of 24 or fewer residues. None of the methods were able to sample loop conformations with near-atomic accuracy for the longest targets ranging from 25 to 32 residues based on 1000 models generated. For these long loop targets, increased conformational sampling is necessary. The strongly conserved disulfide bond between Cys3.25 and Cys45.50 in ECL2 proved an effective filter. Setting an upper limit of 5.1 Å on the S-S distance improved the lowest RMSD model included in the top 10 scored structures in Groups 1-4 on average between 0.33 and 1.27 Å. Disulfide bond formation and geometry optimization of ECL2 provided an additional incremental benefit in structure quality.

GPCR homology model template selection benchmarking: Global versus local similarity measures.

G protein-coupled receptors (GPCR) are integral membrane proteins of considerable interest as targets for drug development. GPCR ligand interaction studies often have a starting point with either crystal structures or comparative models. The majority of GPCR do not have experimentally-characterized 3-dimensional structures, so comparative modeling, also called homology modeling, is a good structure-based starting point. Comparative modeling is a widely used method for generating models of proteins with unknown structures by analogy to crystallized proteins that are expected to exhibit structural conservation. Traditionally, comparative modeling template selection is based on global sequence identity and shared function. However high sequence identity localized to the ligand binding pocket may produce better models to examine protein-ligand interactions. This in silico benchmark study examined the performance of a global versus local similarity measure applied to comparative modeling template selection for 6 previously crystallized, class A GCPR (CXCR4, FFAR1, NOP, P2Y12, OPRK, and M1) with the long-term goal of optimizing GPCR ligand identification efforts. Comparative models were generated from templates selected using both global and local similarity measures. Similarity to reference crystal structures was reflected in RMSD values between atom positions throughout the structure or localized to the ligand binding pocket. Overall, models deviated from the reference crystal structure to a similar degree regardless of whether the template was selected using a global or local similarity measure. Ligand docking simulations were performed to assess relative performance in predicting protein-ligand complex structures and interaction networks. Calculated RMSD values between ligand poses from docking simulations and crystal structures indicate that models based on locally selected templates give docked poses that better mimic crystallographic ligand positions than those based on globally-selected templates in five of the six benchmark cases. However, protein model refinement strategies in advance of ligand docking applications are clearly essential as the average RMSD between crystallographic poses and poses docked into local template models was 9.7 Šand typically less than half of the ligand interaction sites are shared between the docked and crystallographic poses. These data support the utilization of local similarity measures to guide template selection in protocols using comparative models to investigate ligand-receptor interactions.

Shared decision-making (SHARE-D) for healthy behaviour change: a feasibility study in general practice.

BACKGROUND: Effective interventions are needed to support health behaviour change for cardiovascular disease (CVD) prevention. Decision tools encourage behaviour change but their effectiveness when used in shared decision-making with health professionals (HPs) is unknown. AIM: To test the feasibility of using a novel, paper-based tool for shared decision-making in initiating behaviour change. DESIGN & SETTING: A feasibility study in five general practices in Northern Ireland. METHOD: Adults with, or at high risk of, CVD were invited to discuss their diet and physical activity (PA) with an HP. Using a paper-based decision aid in shared decision-making about behaviour change, their capabilities, opportunities, and motivation were considered. Diet and PA were assessed at baseline, 1, and 3 months using the Dietary Instrument for Nutritional Education (DINE) and the Recent Physical Activity Questionnaire (RPAQ); accelerometers measured PA at baseline and 3 months. Semi-structured interviews, analysed thematically, explored participants' and HPs' views of the process. RESULTS: The positive response rate to study invitation was 28% (45/162); 23 were recruited (aged 43-74 years; 50% male; <40% met diet or PA recommendations); and 87% (20/23) completed the study. All interviewees valued the tool's structure, succinct content, and facilitation of discussion. HPs' sharing of relevant personal experience encouraged behaviour change; social responsibilities, health conditions, and beliefs restricted change. HPs' workloads prohibited the tool's routine use. CONCLUSION: Recruitment and completion rates suggest that using a novel, paper-based tool in shared decision-making for behaviour change is feasible. HPs' workloads constrain its use in practice, but qualitative findings indicate its potential value. Cross-sector collaborative exploration of sustainable models to promote behaviour change is needed.

Role of EGF receptor ligands in TCDD-induced EGFR down-regulation and cellular proliferation.

In cultures of normal human epidermal keratinocytes (NHEKs), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces the expression of the epidermal growth factor receptor ligands transforming growth factor-α (TGF-α) and epiregulin (EREG). TCDD also down-regulates EGF receptors (EGFR), suggesting that decreases in signaling contribute to the effects of TCDD. In this study, we treated post-confluent NHEKs with 10 nM TCDD and assessed its effects on EGFR binding, EGFR ligand secretion, basal ERK activity, and proliferation. TCDD caused time-dependent deceases in [(125)I]-EGF binding to levels 78% of basal cell values at 72 h. Amphiregulin (AREG) levels increased with time in culture in basal and TCDD-treated cells, while TGF-α and epiregulin (EREG) secretion were stimulated by TCDD. Inhibiting EGFR ligand release with the metalloproteinase inhibitor batimastat prevented EGFR down-regulation and neutralizing antibodies for AREG and EREG relieved receptor down-regulation. In contrast, neutralizing TGF-α intensified EGFR down-regulation. Treating NHEKs with AREG or TGF-α caused rapid internalization of receptors with TGF-α promoting recycling within 90 min. EREG had limited effects on rapid internalization or recycling. TCDD treatment increased ERK activity, a response reduced by batimastat and the neutralization of all three ligands indicating that the EGFR and its ligands maintain ERK activity. All three EGFR ligands were required for the maintenance of total cell number in basal and TCDD-treated cultures. The EGFR inhibitor PD1530305 blocked basal and TCDD-induced increases in the number of cells labeled by 5-ethynyl-2'-deoxyuridine, identifying an EGFR-dependent pool of proliferating cells that is larger in TCDD-treated cultures. Overall, these data indicate that TCDD-induced EGFR down-regulation in NHEKs is caused by AREG, TGF-α, and EREG, while TGF-α enhances receptor recycling to maintain a pool of EGFR at the cell surface. These receptors are required for ERK activity, maintenance of total cell number, and stimulating the proliferation of a small subset cells.

Frequency of exogenous hormone therapy impacts spermiation in male Fowler's toad (Bufo fowleri).

Amphibians are experiencing a global extinction crisis and captive assurance colonies, along with reintroduction programs, are necessary to prevent further losses. Assisted reproductive technologies (ART), such as hormone-stimulated gamete collection and in vitro fertlisation (IVF), are conservation methods that can be used to increase reproductive output for breeding and reintroduction programs when animals fail to breed naturally. In order to maximise the production of offspring using ART, it is important to establish the physiological limitations on the frequency that hormone therapy can be used to collect gametes for IVF or assisted breeding. The present study examined the effects of the frequency of hormone-induced spermiation on sperm quantity and quality in Fowler's toad (Bufo fowleri) by comparing four levels of hormone injection frequencies: twice a week, once a week, every other week, and every 3 weeks. Sperm release was induced with an intraperitoneal injection of 300IU human chorionic gonadotropin (hCG). Spermatozoa were collected at three time points after injection (5, 7 and 9h) and sperm concentration, motility and quality of forward progressive movement were measured. A significant decrease in sperm concentration (P<0.01) was observed with the most frequent treatment (twice a week hormone injections). However, there was no negative effect of the treatments on sperm motility (P=0.06) or forward movement (P=0.06). We also observed a significant decrease in the concentration (P<0.01), motility (P=0.02) and quality of forward progressive movement (P=0.01) of spermatozoa at the 9h collection compared with earlier collection times. These results have clear implications for amphibian captive breeding programs, where more frequent hormone-induced spermiation could have a negative effect on male performance. We recommend that hormone injections be spaced a minimum of 2 weeks apart to optimise the health of the animals, assisted breeding, IVF or collection of gametes for genome resource banking.

"They should stay at their desk until the work's done": a qualitative study examining perceptions of sedentary behaviour in a desk-based occupational setting.

BACKGROUND: Workplace sedentary behaviour is a priority target for health promotion. However, little is known about how to effect change. We aimed to explore desk-based office workers' perceptions of factors that influenced sedentary behaviour at work and to explore the feasibility of using a novel mobile phone application to track their behaviours. METHODS: We invited office employees (n = 12) and managers (n = 2) in a software engineering company to participate in semi-structured interviews to explore perceived barriers and facilitators affecting workplace sedentary behaviour. We assessed participants' sedentary behaviours using an accelerometer before and after they used a mobile phone application to record their activities at self-selected time intervals daily for 2 weeks. Interviews were analysed using a thematic framework. RESULTS: Software engineers (5 employees; 2 managers) were interviewed; 13 tested the mobile phone application; 8 returned feedback. Major barriers to reducing workplace sedentary behaviour included the pressure of 'getting the job done', the nature of their work requiring sitting at a computer, personal preferences for the use of time at and after work, and a lack of facilities, such as a canteen, to encourage moving from their desks. Facilitators for reduced sedentariness included having a definite reason to leave their desks, social interaction and relief of physical and mental symptoms of prolonged sitting. The findings were similar for participants with different levels of overall physical activity. Valid accelerometer data were tracked for four participants: all reduced their sedentary behaviour. Participants stated that recording data using the phone application added to their day's work but the extent to which individuals perceived this as a burden varied and was counter-balanced by its perceived value in increasing awareness of sedentary behaviour. Individuals expressed a wish for flexibility in its configuration. CONCLUSIONS: These findings indicate that employers' and employees' perceptions of the cultural context and physical environment of their work, as well as personal factors, must be considered in attempting to effect changes that reduce workplace sedentary behaviour. Further research should investigate appropriate individually tailored approaches to this challenge, using a framework of behaviour change theory which takes account of specific work practices, preferences and settings.

Co-cultured tissue-specific scaffolds for tendon/bone interface engineering.

The tendon/ligament-to-bone interface has a complex organization to enable transfer of forces through the tendon/ligament to the bone. The purpose of this study is to create a co-culture environment enabling a tissue-specific tendon region and tissue-specific bone region on a degradable scaffold, using NIH 3T3 fibroblast-deposited extracellular matrix and MC 3T3 osteoblast-deposited extracellular matrix, respectively. Before full characterization of the deposited extracellular matrix coating can be analyzed, co-culture parameters including culture medium and seeding technique should be addressed. An appropriate medium formulation was developed to reduce fibroblast to osteoblast mineralization by adjusting beta-glycerophosphate concentrations. Standard growth medium with fetal bovine serum + 3 mM beta-glycerophosphate + 25 µg/mL ascorbic acid was found to be the most suitable formulation evaluated in these study conditions. Seeding and cell migration studies of co-cultured fibroblast- and osteoblast-specific scaffolds were performed to identify whether tissue regions could be created on the scaffold. Fibroblast and osteoblast regions were successfully seeded and little to no cell migration was observed up to 42 h after seeding. Finally, a preliminary analysis of basic extracellular matrix components was measured in the fibroblast, osteoblast, and transition regions. Tissue-specific DNA, glycosaminoglycan, and collagen were found in uniform amounts on the scaffolds and were not different significantly between scaffold regions. In conclusion, initial steps to create tissue-specific fibroblast and osteoblast regions on a degradable scaffold were successful in preparation for further characterization investigations as a tendon-to-bone interface scaffold.

Using postal questionnaires to evaluate physical activity and diet behaviour change: case study exploring implications of valid responder characteristics in interpreting intervention outcomes.

BACKGROUND: Patient reported outcome measures (PROMs) are used to evaluate lifestyle interventions but little is known about differences between patients returning valid and invalid responses, or of potential for bias in evaluations. We aimed to examine the characteristics of patients who returned valid responses to lifestyle questionnaires compared to those whose responses were invalid for evaluating lifestyle change. METHODS: We conducted a secondary data analysis from the SPHERE Study, a trial of an intervention to improve outcomes for patients with coronary heart disease in primary care. Postal questionnaires were used to assess physical activity (Godin) and diet (DINE) among study participants at baseline and 18 month follow-up. Three binary response variables were generated for analysis: (1) valid Godin score; (2) valid DINE Fibre score; and (3) valid DINE Total Fat score. Multivariate analysis comprised generalised estimating equation regression to examine the association of patients' characteristics with their return of valid responses at both timepoints. RESULTS: Overall, 92.1% of participants (832/903) returned questionnaires at both baseline and 18 months. Relatively fewer valid Godin scores were returned by those who left school aged <15 years (36.5%) than aged 18 and over (50.5%), manual workers (39.5%) than non-manual (49.5%) and those with an elevated cholesterol (>5 mmol) (34.7%) than those with a lower cholesterol (44.4%) but multivariate analysis identified that only school leaving age (p = 0.047) was of statistical significance.Relatively fewer valid DINE scores were returned by manual than non-manual workers (fibre: 80.8% v 86.8%; fat: 71.2% v 80.0%), smokers (fibre: 72.6% v 84.7%; fat: 67.5% v 76.9%), patients with diabetes (fibre: 75.9% v 82.9%; fat: 66.9% v 75.8%) and those with cholesterol >5 mmol (fat: 68.2% v 76.2%) but multivariate analysis showed statistical significance only for smoking (fibre: p = 0.013; fat: p = 0.045), diabetes (fibre: p = 0.039; fat: p = 0.047), and cholesterol (fat: p = 0.039). CONCLUSIONS: Our findings illustrate the importance of detailed reporting of research methods, with clear information about response rates, respondents and valid outcome data. Outcome measures which are relevant to a study population should be chosen carefully. The impact of methods of outcome measurement and valid response rates in evaluating healthcare requires further study.

Modeling long-term host cell-Giardia lamblia interactions in an in vitro co-culture system.

Globally, there are greater than 700,000 deaths per year associated with diarrheal disease. The flagellated intestinal parasite, Giardia lamblia, is one of the most common intestinal pathogens in both humans and animals throughout the world. While attached to the gastrointestinal epithelium, Giardia induces epithelial cell apoptosis, disrupts tight junctions, and increases intestinal permeability. The underlying cellular and molecular mechanisms of giardiasis, including the role lamina propria immune cells, such as macrophages, play in parasite control or clearance are poorly understood. Thus far, one of the major obstacles in ascertaining the mechanisms of Giardia pathology is the lack of a functionally relevant model for the long-term study of the parasite in vitro. Here we report on the development of an in vitro co-culture model which maintains the basolateral-apical architecture of the small intestine and allows for long-term survival of the parasite. Using transwell inserts, Caco-2 intestinal epithelial cells and IC-21 macrophages are co-cultured in the presence of Giardia trophozoites. Using the developed model, we show that Giardia trophozoites survive over 21 days and proliferate in a combination media of Caco-2 cell and Giardia medium. Giardia induces apoptosis of epithelial cells through caspase-3 activation and macrophages do not abrogate this response. Additionally, macrophages induce Caco-2 cells to secrete the pro-inflammatory cytokines, GRO and IL-8, a response abolished by Giardia indicating parasite induced suppression of the host immune response. The co-culture model provides additional complexity and information when compared to a single-cell model. This model will be a valuable tool for answering long-standing questions on host-parasite biology that may lead to discovery of new therapeutic interventions.

Prostaglandin E(2) in tick saliva regulates macrophage cell migration and cytokine profile.

BACKGROUND: Ticks are obligate hematophagous ectoparasites that suppress the host's immune and inflammatory responses by secreting immuno-modulatory and anti-inflammatory molecules in their saliva. In previous studies we have shown that tick salivary gland extract (SGE) and saliva from Dermacentor variabilis have distinct effects on platelet-derived growth factor (PDGF)-stimulated IC-21 macrophage and NIH3T3-L1 fibroblast migration. Since tick saliva contains a high concentration of prostaglandin E2 (PGE2), a potent modulator of inflammation, we used a PGE2 receptor antagonist to evaluate the role of PGE2 in the different migratory responses induced by saliva and its impact on macrophage cytokine profile. METHODS: Adult ticks were fed on female New Zealand white rabbits for 5-8 days. Female ticks were stimulated with dopamine/theophylline to induce salivation and saliva was pooled. Competitive enzyme immunoassays (EIA) were used to measure saliva PGE2 content and the changes in macrophage intracellular cyclic adenosine monophosphate (cAMP) levels. The effects of tick saliva on macrophage and fibroblast migration were assessed in the absence and presence of the PGE2 receptor antagonist, AH 6809, using blind well chamber assays. A cytokine antibody array was used to examine the effects of tick saliva on macrophage cytokine secretion. Statistical significance was determined by one-way ANOVA; Student Newman-Kuels post-test was used for multiple comparisons. RESULTS: The saliva-induced increase in PDGF-stimulated macrophage migration was reversed by AH 6809. The inhibition of PDGF-stimulated fibroblast migration by saliva was also antagonist-sensitive. Tick saliva induced macrophages to secrete copious amounts of PGE2, and conditioned medium from these cells caused an AH 6809-sensitive inhibition of stimulated fibroblast migration, showing that macrophages can regulate fibroblast activity. We show that tick saliva decreased the secretion of the pro-inflammatory cytokines regulated and normal T cell expressed and secreted (RANTES/CCL5), tumor necrosis factor-alpha (TNF-α), and soluble TNF receptor I (sTNFRI) through a PGE2-dependent mechanism mediated by cAMP. Saliva had similar effects on lipopolysaccharide (LPS) stimulated macrophages. CONCLUSIONS: Our data show that ticks utilize salivary PGE2 to subvert the ability of macrophages to secrete pro-inflammatory mediators and recruit fibroblasts to the feeding lesion, therefore inhibiting wound healing.

Do practitioners and friends support patients with coronary heart disease in lifestyle change? a qualitative study.

BACKGROUND: Healthy lifestyles help to prevent coronary heart disease (CHD) but outcomes from secondary prevention interventions which support lifestyle change have been disappointing. This study is a novel, in-depth exploration of patient factors affecting lifestyle behaviour change within an intervention designed to improve secondary prevention for patients with CHD in primary care using personalised tailored support. We aimed to explore patients' perceptions of factors affecting lifestyle change within a trial of this intervention (the SPHERE Study), using semi-structured, one-to-one interviews, with patients in general practice. METHODS: Interviews (45) were conducted in purposively selected general practices (15) which had participated in the SPHERE Study. Individuals, with CHD, were selected to include those who succeeded in improving physical activity levels and dietary fibre intake and those who did not. We explored motivations, barriers to lifestyle change and information utilised by patients. Data collection and analysis, using a thematic framework and the constant comparative method, were iterative, continuing until data saturation was achieved. RESULTS: We identified novel barriers to lifestyle change: such disincentives included strong negative influences of social networks, linked to cultural norms which encouraged consumption of 'delicious' but unhealthy food and discouraged engagement in physical activity. Findings illustrated how personalised support within an ongoing trusted patient-professional relationship was valued. Previously known barriers and facilitators relating to support, beliefs and information were confirmed. CONCLUSIONS: Intervention development in supporting lifestyle change in secondary prevention needs to more effectively address patients' difficulties in overcoming negative social influences and maintaining interest in living healthily.

Effects of tick saliva on the migratory and invasive activity of Saos-2 osteosarcoma and MDA-MB-231 breast cancer cells.

In previous studies we showed that tick saliva modulates the migratory activity of cells involved in the wound healing response. Since cell migration is a prerequisite for tumor invasion and metastasis, we examined the effects of tick saliva on the migratory and invasive activity of Saos-2 osteosarcoma and MDA-MB-231 (MB-231) breast cancer cells and the potential signaling pathways that may be affected. Saliva inhibited basal and agonist-induced Saos-2 and MB-231 migration and invasion through a matrigel-coated filter. In the Saos-2 cells, saliva suppressed epidermal growth factor (EGF)-activation of Akt/Protein Kinase B, however, only basal extracellular signal-regulated kinase (ERK) activity was affected in MB-231 cells. EGF receptor (EGFR) overexpression masked the effect of saliva on MB-231 cells, but its ability to inhibit MB-231 migration was enhanced by the EGFR inhibitor PD 168393 and MEK inhibitor U0126. Our data indicate that the mechanisms ticks have evolved to regulate the wound healing response have generalized effects on the migratory and invasive activities of metastatic cancer cells.

Hematoma-inspired alginate/platelet releasate/CaPO4 composite: initiation of the inflammatory-mediated response associated with fracture repair in vitro and ex vivo injection delivery.

A clinical need continues for consistent bone remodeling within problematic sites such as those of fracture nonunion, avascular necrosis, or irregular bone formations. In attempt to address such needs, a biomaterial system is proposed to induce early inflammatory responses after implantation and to provide later osteoconductive scaffolding for bone regeneration. Biomaterial-induced inflammation would parallel the early stage of hematoma-induced fracture repair and allow scaffold-promoted remodeling of osseous tissue to a healthy state. Initiation of the wound healing cascade by two human concentrated platelet releasate-containing alginate/ß-tricalcium phosphate biocomposites has been studied in vitro using the TIB-71™ RAW264.7 mouse monocyte cell line. Inflammatory responses inherent to the base material were found and could be modulated through incorporation of platelet releasate. Differences in hydrogel wt% (2 vs. 8 %) and/or calcium phosphate granule vol.% (20 vs. 10 %) allowed for tuning the response associated with platelet releasate-associated growth factor elution. Tunability from completely suppressing the inflammatory response to augmenting the response was observed through varied elution profiles of both releasate-derived bioagents and impurities inherent to alginate. A 2.5-fold upregulation of inducible-nitric oxide synthase gene expression followed by a tenfold increase in nitrite media levels was induced by inclusion of releasate within the 8 wt%/10 vol.% formulation and was comparable to an endotoxin positive control. Whereas, near complete elimination of inflammation was seen when releasate was included within the 2 wt%/20 vol.% formulation. These in vitro results suggested tunable interactions between the multiple platelet releasate-derived bioagents and the biocomposites for enhancing hematoma-like fracture repair. Additionally, minimally invasive delivery for in situ curing of the implant system via injection was demonstrated in rat tail vertebrae using microcomputed tomography.

Investigation of polyurea-crosslinked silica aerogels as a neuronal scaffold: a pilot study.

BACKGROUND: Polymer crosslinked aerogels are an attractive class of materials for future implant applications particularly as a biomaterial for the support of nerve growth. The low density and nano-porous structure of this material combined with large surface area, high mechanical strength, and tunable surface properties, make aerogels materials with a high potential in aiding repair of injuries of the peripheral nervous system. however, the interaction of neurons with aerogels remains to be investigated. METHODOLOGY: In this work the attachment and growth of neurons on clear polyurea crosslinked silica aerogels (PCSA) coated with: poly-L-lysine, basement membrane extract (BME), and laminin1 was investigated by means of optical and scanning electron microscopy. After comparing the attachment and growth capability of neurons on these different coatings, laminin1 and BME were chosen for nerve cell attachment and growth on PCSA surfaces. The behavior of neurons on treated petri dish surfaces was used as the control and behavior of neurons on treated PCSA discs was compared against it. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that: 1) untreated PCSA surfaces do not support attachment and growth of nerve cells, 2) a thin application of laminin1 layer onto the PCSA discs adhered well to the PCSA surface while also supporting growth and differentiation of neurons as evidenced by the number of processes extended and b3-tubulin expression, 3) three dimensional porous structure of PCSA remains intact after fixing protocols necessary for preservation of biological samples and 4) laminin1 coating proved to be the most effective method for attaching neurons to the desired regions on PCSA discs. This work provides the basis for potential use of PCSA as a biomaterial scaffold for neural regeneration.

Induction of the early inflammatory-mediated cellular responses of fracture healing in vitro using platelet releasate-containing alginate/CaPO4 biomaterials for early osteoarthritis prevention.

A significant gap exists in our understanding of subchondral and cancellous bone changes that may regulate osteoarthritis progression. Herein, we complement our prior osteochondrogenesis work with growth factor elution and monocyte and endothelial cell activation using two biomaterial formulations. The design of these biomaterials was inspired by the roles of a fracture hematoma, more specifically, the potential of significant cross-talk among cells and cellular factors that affect bone remodeling. Biomaterials, referred to herein as F1+ and F2+, are human concentrated platelet releasate-containing alginate/beta-tricalcium phosphate composites. F1+ has a higher calcium phosphate volume percentage and lower alginate polymer weight percent hydrogel versus F2+. The majority of releasate-derived platelet-derived growth factor eluted over 24 h for F1+ and 48 h for F2+, suggesting sustained release with an increase in alginate weight percentage. Simple monocyte and endothelial cell migration studies demonstrated 650% and 900% increases with F1+ eluate over medium alone, respectively. Induction of endothelial cell invasion over supplemented medium positive control was also shown for F2+ eluate (p = 0.03) with F1+ eluate being similar to the control. Monocyte transendothelial migration was increased over 300% and 400% for F1+ and F2+ eluates compared with medium alone, respectively. In addition, F1+ and F2+ eluates induced spontaneous endothelial tube formations similar to supplemented medium, demonstrating a well-formed network of capillary-like structures. This work demonstrated our biomaterial formulations ability to induce characteristics in vitro that parallel the in vivo behavior of fracture hematomas and potential to induce bone remodeling for the early treatment of osteoarthritic joints.

In vitro differentiation and biocompatibility of mesenchymal stem cells on a novel platelet releasate-containing injectable composite.

Underlying changes in subchondral and cancellous bone precede joint degeneration in spinal discs, knees, hips, and other joints. We hypothesize that an early bone remodeling intervention therapy may alleviate or postpone the later manifestation of joint failure. Utilization of a novel biomaterial for injection deliverability to the underlying subchondral and cancellous bone during the onset of osseous changes, before severe cartilaginous damage, is proposed. In this preliminary study, we introduced novel platelet releasate-containing alginate/calcium phosphate composites for this intervention therapy and evaluated them in vitro through mesenchymal stem cell biocompatibility and induction of osteochondral differentiation. DNA quantification and gene expression profiles suggested mesenchymal stem cells were directed along an osteochondral differentiation pathway, more specifically, to the immature nonhypertrophic chondrocyte phenotype. These conclusions were based on reduced mitogenic activity, a rapid upregulation followed by suppression of Runx2 transcription factor mRNA, sustained upregulation of Sox9 transcription factor mRNA and the absence of late marker expressions for both mature articular chondrocytes and osteoblasts over the course of 14 days. Initial findings in regard to the use of these materials for bone remodeling were positive and support the execution of future studies evaluating the inflammatory and angiogenic aspects of the materials. In this study, we have considered one of the many aspects of the endochondral ossification process; neovascularization and resorption of bone with an irregular physiology need to be evaluated.