Best practices for germ-free derivation and gnotobiotic zebrafish husbandry

All animals are ecosystems with resident microbial communities, referred to as microbiota, which play profound roles in host development, physiology, and evolution. Enabled by new DNA sequencing technologies, there is a burgeoning interest in animal-microbiota interactions, but dissecting the specific impacts of microbes on their hosts is experimentally challenging. Gnotobiology, the study of biological systems in which all members are known, enables precise experimental analysis of the necessity and sufficiency of microbes in animal biology by deriving animals germ-free (GF) and inoculating them with defined microbial lineages. Mammalian host models have long dominated gnotobiology, but we have recently adapted gnotobiotic approaches to the zebrafish (Danio rerio), an important aquatic model. Zebrafish offer several experimental attributes that enable rapid, large-scale gnotobiotic experimentation with high replication rates and exquisite optical resolution. Here we describe detailed protocols for three procedures that form the foundation of zebrafish gnotobiology: derivation of GF embryos, microbial association of GF animals, and long-term, GF husbandry. Our aim is to provide sufficient guidance in zebrafish gnotobiotic methodology to expand and enrich this exciting field of research.

Skeletal muscle action of estrogen receptor α is critical for the maintenance of mitochondrial function and metabolic homeostasis in females

Impaired estrogen receptor α (ERα) action promotes obesity and metabolic dysfunction in humans and mice; however, the mechanisms underlying these phenotypes remain unknown. Considering that skeletal muscle is a primary tissue responsible for glucose disposal and oxidative metabolism, we established that reduced ERα expression in muscle is associated with glucose intolerance and adiposity in women and female mice. To test this relationship, we generated muscle-specific ERα knockout (MERKO) mice. Impaired glucose homeostasis and increased adiposity were paralleled by diminished muscle oxidative metabolism and bioactive lipid accumulation in MERKO mice. Aberrant mitochondrial morphology, overproduction of reactive oxygen species, and impairment in basal and stress-induced mitochondrial fission dynamics, driven by imbalanced protein kinase A-regulator of calcineurin 1-calcineurin signaling through dynamin-related protein 1, tracked with reduced oxidative metabolism in MERKO muscle. Although muscle mitochondrial DNA (mtDNA) abundance was similar between the genotypes, ERα deficiency diminished mtDNA turnover by a balanced reduction in mtDNA replication and degradation. Our findings indicate the retention of dysfunctional mitochondria in MERKO muscle and implicate ERα in the preservation of mitochondrial health and insulin sensitivity as a defense against metabolic disease in women.

Role of staging laparoscopy in the stratification of patients with perihilar cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma is a rare cancer with a poor prognosis. Radical surgical resection is the only option for curative treatment. Optimal determination of resectability is required so that patients can be stratified into operative or chemotherapeutic treatment cohorts in an accurate and time-efficient manner. Staging laparoscopy is utilized to determine the presence of radiologically occult disease that would preclude further surgical treatment. The aim of this study was to analyse the utility of staging laparoscopy in a contemporary cohort of patients with perihilar cholangiocarcinoma.

METHODS

Patients diagnosed with potentially resectable perihilar cholangiocarcinoma between January 2010 and April 2015 were analysed retrospectively from a prospective database linked to UK Hospital Episode Statistics data. Patients with distal cholangiocarcinoma and gallbladder cancer were excluded from analysis.

RESULTS

A total of 431 patients with perihilar cholangiocarcinoma were referred for assessment of potential resection at a supraregional referral centre. Some 116 patients with potentially resectable disease subsequently underwent surgical assessment. The cohort demonstrated an all-cause yield of staging laparoscopy for unresectable disease of 27·2 per cent (31 of 114). The sensitivity for detection of peritoneal disease was 71 per cent (15 of 21; P < 0·001). The accuracy for all-cause non-resection for staging laparoscopy was 66 per cent (31 of 47) with a positive predictive value of progress to resection of 81 per cent (69 of 85). Neither the Bismuth-Corlette nor the Memorial Sloan Kettering Cancer Center preoperative scoring system was contingent with cause of unresectability at staging laparoscopy (P = 0·462 and P = 0·280 respectively).

CONCLUSION

In the present cohort, staging laparoscopy proved useful in determining the presence of radiologically occult metastatic disease in perihilar cholangiocarcinoma.

Stepped-wedge cluster randomised controlled trial to assess the effectiveness of an electronic medication management system to reduce medication errors, adverse drug events and average length of stay at two paediatric hospitals: a study protocol

INTRODUCTION

Medication errors are the most frequent cause of preventable harm in hospitals. Medication management in paediatric patients is particularly complex and consequently potential for harms are greater than in adults. Electronic medication management (eMM) systems are heralded as a highly effective intervention to reduce adverse drug events (ADEs), yet internationally evidence of their effectiveness in paediatric populations is limited. This study will assess the effectiveness of an eMM system to reduce medication errors, ADEs and length of stay (LOS). The study will also investigate system impact on clinical work processes.

METHODS AND ANALYSIS

A stepped-wedge cluster randomised controlled trial (SWCRCT) will measure changes pre-eMM and post-eMM system implementation in prescribing and medication administration error (MAE) rates, potential and actual ADEs, and average LOS. In stage 1, 8 wards within the first paediatric hospital will be randomised to receive the eMM system 1 week apart. In stage 2, the second paediatric hospital will randomise implementation of a modified eMM and outcomes will be assessed. Prescribing errors will be identified through record reviews, and MAEs through direct observation of nurses and record reviews. Actual and potential severity will be assigned. Outcomes will be assessed at the patient-level using mixed models, taking into account correlation of admissions within wards and multiple admissions for the same patient, with adjustment for potential confounders. Interviews and direct observation of clinicians will investigate the effects of the system on workflow. Data from site 1 will be used to develop improvements in the eMM and implemented at site 2, where the SWCRCT design will be repeated (stage 2).

ETHICS AND DISSEMINATION

The research has been approved by the Human Research Ethics Committee of the Sydney Children's Hospitals Network and Macquarie University. Results will be reported through academic journals and seminar and conference presentations.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ANZCTR) 370325.

Spring Ligament Tear Decreases the Ankle and Talonavicular Joint Reaction Forces

Category:

Other

Introduction/Purpose:

Spring ligament tear is often noted in advanced stages of the adult acquired flatfoot deformity (AAFD). Previous anatomic studies demonstrated that the spring and deltoid ligaments are not separate structure, but form a confluent ligament in which the tibiocalcaneonavicular ligament (TCNL) comprises the largest component. A biomechanical study which utilized stage IIB AAFD model demonstrated inferior result of the anatomic spring ligament reconstruction compared to the tibionavicular ligament reconstruction. Therefore, the TCNL reconstruction has been proposed for effective restoration of the ankle and talonavicular joints stability in AAFD with a large spring ligament tear. We aimed to investigate if spring ligament tear of greater than 1.5 cm decreases the ankle and talonavicular joint reaction forces (JRF), and if they could be restored by the TCNL reconstruction.

Methods:

Ten fresh-frozen human cadaveric lower legs were obtained and disarticulated at the knee joint. Steinmann pins were percutaneously placed across the distal tibia, center of the talus and navicular while preserving adjacent soft tissues. A distraction force was applied across the ankle and talonavicular joints to determine the baseline force displacement curve to generate a best- fit polynomial equation to determine normal JRF. A spring ligament injury model was created by releasing the medial capsuloligamentous complex of the talonavicular joint and extending the resection 1.5 cm proximally. The TCNL reconstruction was performed with a forked semitendinosus allograft. The folded portion of the graft was fixed to the medial malleolar inter- colliculus. One limb of the separated part of the allograft was fixed to the navicular tuberosity and the other limb was fixed to the calcaneus below the sustentaculum tali. The resultant JRFs across the tibiotalar and talonavicular joints were measured after each step.

Results:

The mean baseline JRFs of the ankle and talonavicular joints were 8.36 N +/- 1.8 N and 3.01 N +/- 0.9 N, respectively. The spring ligament tear resulted in 29% decrease in tibiotalar JRF (5.97 N +/- 1.1 N, p< 0.05) and 13% decrease in talonavicular JRF (2.63 N +/- 0.8 N, p>0.05). Although the tibionavicular ligament reconstruction partially restored JRFs of the tibiotalar (7.83 +/- 2.4 N, p> 0.05) and talonavicular joints (4.08 N +/- 1.8 N, p> 0.05), they were not statistically significant. Addition of the tibiocalcaneal ligament reconstruction resulted in significantly increased JRFs of the tibiotalar (9.17 +/- 3.93 N, p> 0.05) and talonavicular joints (4.35 +/- 2.04 N, p> 0.05) compared to the spring ligament injury model.

Conclusion:

This is the first biomechanical study to demonstrate that a large size (>1.5 cm) spring ligament tear results in decreased JRF of the ankle joint. The decreased ankle and talonavicular JRFs were effectively restored by the novel TCNL reconstruction. This technique utilizes a forked allograft with two limbs for the tibionavicular and tibiocalcaneal ligaments reconstructions. Advanced AAFD with a large size spring ligament tear may have medial ankle instability that should not be overlooked. The novel TCNL reconstruction should be considered to prevent progression of valgus deformity. The biomechanical and clinical efficacies of the TCNL reconstruction warrant further investigation.

A Novel Method for Measurement of Ankle Joint Reaction Force and Response to Syndesmotic Injury

Category:

Ankle.

Introduction/Purpose:

Increasing evidence has suggested that alterations in joint mechanics results in articular pathology. Previous studies demonstrated noninvasive measurements of joint reactive forces (JRF) can be performed reliably without destruction of the peri-articular soft tissue in medium and small size joints of the upper extremity. This study presents a novel, noninvasive measurement of the JRF to investigate the normal and the effects of a syndesmotic injury. The JRF of the tibiotalar joint was also evaluated following anatomic reduction with fixation and malreduction of the syndesmosis.

Methods:

Eight fresh-frozen human cadaveric lower extremity limbs were obtained disarticulated above the knee. A distraction force was applied across the tibio-talar joint to determine the baseline (normal) ankle force displacement curve. Next, a syndesmotic injury was created by releasing the interosseous syndesmotic ligaments, the transverse tibiofibular ligament and the anterior and posterior tibiofibular ligaments. Prior to sectioning, two drill holes were placed across the joint and tapped to ensure anatomic reduction. JRF were measured using a quadricortical technique with a single or double screw configuration. The syndesmosis was malreduced by anteriorly displacing the fibula 5 mm. After each step, the resultant JRFs were determined using a distraction force across the tibiotalar joint.

Results:

Force displacement curves obtained from multiple measurements from each specimen with a mean ankle JRF of 31.4 + 2.6 N. Syndesmotic injury resulted in a 35% decrease in tibiotalar JRF (20.3 + 3.0 N, p=0.002). Fixation of the injury using one syndesmotic screw resulted in significant increase in JRF compared to injury JRF (28.7 + 1.4 N, p=0.02). Syndesmotic fixation with 2 screws also demonstrated a trend towards restoration of tibiotalar JRF (28.3 + 2.2 N, p=0.06). There was no statistical difference between fixation of one versus two syndesmotic screws. The JRF for the malreduced syndesmosis was 31.5 + 1.8 N (p=0.03,) resulting in increased forces approaching the baseline JRF.

Conclusion:

This study demonstrates a non-destructive model by which to measure joint reactive forces (JRF) across the tibiotalar joint and that these forces are diminished as a result of a syndesmotic injury, suggesting joint instability. Surgical stabilization with either 1 or 2 screws creates JRF that are similar to the normal JRF. Even with a malreduced syndesmosis, there appeared to be a JRF similar to baseline tibiotalar joint forces. However malreduction of the syndesmosis may alter the joint dynamics of the ankle in ways that were not measured in this study.

Trust: The Missing Dimension in the Food Retail Transition in Thailand

Thailand has experienced dramatic growth of large national and international modern food retailers, such as supermarkets, hypermarkets and convenience stores in large cities and regional centres in the last two decades. Nevertheless, Thai consumers continue to purchase perishables (fruits, vegetables and animal products) from fresh markets (wet markets, talat sot) contradicting predictions from analysts that modern food retail chains will rapidly replace fresh markets as the preferred venue for purchasing all types of foods. This paper examines trust in food retail systems as an under-explored dimension lying behind the continued patronage by Thais of fresh markets to purchase perishable items. It derives from a research program commenced in 2005 that includes fieldwork visits, interviews and questionnaires. In the context of the Thai food retail transition, we propose that trust affects relationships between consumers and (1) individual fresh market-based vendors, (2) the food products sold at fresh markets and (3) the food retail system more broadly. If fresh markets can be maintained in the face of sustained pressure from modern national and international food retailers, Thais will continue to use them. Meanwhile, trust is a relatively unrecognised dimension that is supporting the continued existence of traditional food retail formats.

Exposure of the grass shrimp, Palaemonetes pugio, to antimicrobial compounds affects associated Vibrio bacterial density and development of antibiotic resistance

Antimicrobial compounds are widespread, emerging contaminants in the aquatic environment and may threaten ecosystem and human health. This study characterized effects of antimicrobial compounds common to human and veterinary medicine, aquaculture, and consumer personal care products [erythromycin (ERY), sulfamethoxazole (SMX), oxytetracycline (OTC), and triclosan (TCS)] in the grass shrimp Palaemonetes pugio. The effects of antimicrobial treatments on grass shrimp mortality and lipid peroxidation activity were measured. The effects of antimicrobial treatments on the bacterial community of the shrimp were then assessed by measuring Vibrio density and testing bacterial isolates for antibiotic resistance. TCS (0.33 mg/L) increased shrimp mortality by 37% and increased lipid peroxidation activity by 63%. A mixture of 0.33 mg/L TCS and 60 mg/L SMX caused a 47% increase in shrimp mortality and an 88% increase in lipid peroxidation activity. Exposure to SMX (30 mg/L or 60 mg/L) alone and to a mixture of SMX/ERY/OTC did not significantly affect shrimp survival or lipid peroxidation activity. Shrimp exposure to 0.33 mg/L TCS increased Vibrio density 350% as compared to the control whereas SMX, the SMX/TCS mixture, and the mixture of SMX/ERY/OTC decreased Vibrio density 78-94%. Increased Vibrio antibiotic resistance was observed for all shrimp antimicrobial treatments except for the mixture of SMX/ERY/OTC. Approximately 87% of grass shrimp Vibrio isolates displayed resistance to TCS in the control treatment suggesting a high level of TCS resistance in environmental Vibrio populations. The presence of TCS in coastal waters may preferentially increase the resistance and abundance of pathogenic bacteria. These results indicate the need for further study into the potential interactions between antimicrobials, aquatic organisms, and associated bacterial communities.

Mechanoresponsive Properties of the Periodontal Ligament

The periodontal ligament (PDL) functions as an enthesis, a connective tissue attachment that dissipates strains created by mechanical loading. Entheses are mechanoresponsive structures that rapidly adapt to changes in their mechanical loading; here we asked which features of the PDL are sensitive to such in vivo loading. We evaluated the PDL in 4 physiologically relevant mechanical environments, focusing on mitotic activity, cell density, collagen content, osteogenic protein expression, and organization of the tissue. In addition to examining PDLs that supported teeth under masticatory loading and eruptive forces, 2 additional mechanical conditions were created and analyzed: hypoloading and experimental tooth movement. Collectively, these data revealed that the adult PDL is a remarkably quiescent tissue and that only when it is subjected to increased loads—such as those associated with mastication, eruption, and orthodontic tooth movement—does the tissue increase its rate of cell proliferation and collagen production. These data have relevance in clinical scenarios where PDL acclimatization can be exploited to optimize tooth movement.

Biological Augmentation of Flexor Tendon Repair: A Challenging Cellular Landscape

Advances in surgical technique and rehabilitation have transformed zone II flexor tendon injuries from an inoperable no-man's land to a standard surgical procedure. Despite these advances, many patients develop substantial range of motion-limiting adhesions after primary flexor tendon repair. These suboptimal outcomes may benefit from biologic augmentation or intervention during the flexor tendon healing process. However, there is no consensus biological approach to promote satisfactory flexor tendon healing; we propose that insufficient understanding of the complex cellular milieu in the healing tendon has hindered the development of successful therapies. This article reviews recent advances in our understanding of the cellular components of flexor tendon healing and adhesion formation, including resident tendon cells, synovial sheath, macrophages, and bone marrow-derived cells. In addition, it examines molecular approaches that have been used in translational animal models to improve flexor tendon healing and gliding function, with a specific focus on progress made using murine models of healing. This information highlights the importance of understanding and potentially exploiting the heterogeneity of the cellular environment during flexor tendon healing, to define rational therapeutic approaches to improve healing outcomes.

Transcriptomes of post-mitotic neurons identify the usage of alternative pathways during adult and embryonic neuronal differentiation

Background

Understanding the mechanisms by which neurons are generated and specified, and how they integrate into functional circuits is key to being able to treat disorders of the nervous system and acute brain trauma. Much of what we know about neuronal differentiation has been studied in developing embryos, but differentiation steps may be very different during adult neurogenesis. For this reason, we compared the transcriptomes of newly differentiated neurons in zebrafish embryos and adults.

Results

Using a 4tU RNA labeling method, we isolated and sequenced mRNA specifically from cells of one day old embryos and adults expressing the transgene HA-uprt-mcherry under control of the neuronal marker elavl3. By categorizing transcript products into different protein classes, we identified similarities and differences of gene usage between adult and embryonic neuronal differentiation. We found that neurons in the adult brain and in the nervous system of one day old embryos commonly use transcription factors - some of them identical - during the differentiation process. When we directly compared adult differentiating neurons to embryonic differentiating neurons, however, we found that during adult neuronal differentiation, the expression of neuropeptides and neurotransmitter pathway genes is more common, whereas classical developmental signaling through secreted molecules like Hedgehog or Wnt are less enriched, as compared to embryonic stages.

Conclusions

We conclude that both adult and embryonic differentiating neurons show enriched use of transcription factors compared to surrounding cells. However, adult and embryonic developing neurons use alternative pathways to differentiate. Our study provides evidence that adult neuronal differentiation is distinct from the better characterized embryonic neuronal differentiation process. This important insight and the lists of enriched genes we have identified will now help pave the way to a better understanding of the mechanisms of embryonic and adult neuronal differentiation and how to manipulate these processes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-2215-8) contains supplementary material, which is available to authorized users.

Kidney disease in antiretroviral-naïve HIV-positive adults with high CD4 counts: prevalence and predictors of kidney disease at enrolment in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

HIV infection has been associated with an increased risk of chronic kidney disease (CKD). Little is known about the prevalence of CKD in individuals with high CD4 cell counts prior to initiation of antiretroviral therapy (ART). We sought to address this knowledge gap.

METHODS

We describe the prevalence of CKD among 4637 ART-naïve adults (mean age 36.8 years) with CD4 cell counts > 500 cells/μL at enrolment in the Strategic Timing of AntiRetroviral Treatment (START) study. CKD was defined by estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2) and/or dipstick urine protein ≥ 1+. Logistic regression was used to identify baseline characteristics associated with CKD.

RESULTS

Among 286 [6.2%; 95% confidence interval (CI) 5.5%, 6.9%] participants with CKD, the majority had isolated proteinuria. A total of 268 participants had urine protein ≥ 1+, including 41 with urine protein ≥ 2+. Only 22 participants (0.5%) had an estimated glomerular filtration rate < 60 mL/min/1.73 m(2) , including four who also had proteinuria. Baseline characteristics independently associated with CKD included diabetes [adjusted odds ratio (aOR) 1.73; 95% CI 1.05, 2.85], hypertension (aOR 1.82; 95% CI 1.38, 2.38), and race/ethnicity (aOR 0.59; 95% CI 0.37, 0.93 for Hispanic vs. white).

CONCLUSIONS

We observed a low prevalence of CKD associated with traditional CKD risk factors among ART-naïve clinical trial participants with CD4 cell counts > 500 cells/μL.

Fitness to drive in cognitive impairment--a quantitative study of GPs' experience

Assessing fitness to drive is part of the role of general practitioners. Cognitive impairment may affect an individual's ability to drive safely. The aims of our study were to question GPs about their experience of assessing patients with cognitive impairment for driving fitness and to explore their attitudes to this role. We carried out a quantitative cross-sectional anonymous postal survey of 200 GPs in counties Galway, Mayo and Roscommon. Ethical approval was obtained from the Irish College of General Practitioners. Data was analysed using Epi Info. The response rate was 62.5% (n=125). 86 (68.8%) GPs used guidelines when assessing fitness to drive in cognitive impairment. 83 (66.4%) respondents formally assess cognitive function. 52 (41.6%) GPs would certify someone as fit to drive with verbal restrictions. 102 (81.6%) respondents feel confident in assessing fitness to drive. 98 (78.4%) GPs have referred patients for further assessment.

Performance of influenza-specific triage tools in an H1N1-positive cohort: P/F ratio better predicts the need for mechanical ventilation and critical care admission

BACKGROUND

Pandemic influenza presents a major threat to global health and socioeconomic well-being. Future demand for critical care may outstrip supply and force clinicians to triage patients for admission. We evaluated the Simple Triage Scoring System (STSS), Ontario Health Plan for an Influenza Epidemic (OHPIP) and PaO2 /FiO2  (P/F) ratio to determine utility in predicting need for mechanical ventilation.

METHODS

We conducted a retrospective case note review of patients admitted to two centres, Royal Liverpool University Hospital and Countess of Chester Hospital, during the UK influenza pandemic of 2010-11. Demand for critical care during this period forced hospitals in Cheshire and Merseyside to implement escalation policies and increase capacity. Inclusion criteria were polymerase chain reaction-confirmed H1N1 influenza and age >18 years. Exclusion criteria were no evidence of treatment for influenza, patient not admitted to hospital or the inability to locate case notes.

RESULTS

One hundred and one patients were included, 29 were admitted to critical care and 23 required mechanical ventilation. The P/F ratio predicted the need for mechanical ventilation with a receiver operating characteristic area under the curve (ROC AUC) of 0.885 (CI 0.817-0.952). Predictive ability was not reduced when the P/F ratio had to be estimated using the Pandharipande tool. The STSS score predicted the need for mechanical ventilation [ROC AUC 0.798 (CI 0.704-0.891)]. The reverse triage component of the OHPIP tool was a poor predictor of patient outcome.

CONCLUSIONS

The P/F ratio was a better predictor of need for mechanical ventilation than STSS. The P/F ratio is a simple and accepted determinant of hypoxaemia and should be used if secondary triaging becomes necessary during future influenza pandemics.

Small pipes: preliminary experience with 3-mm or smaller pipeline flow-diverting stents for aneurysm repair prior to regulatory approval

Flow diversion has become an established treatment option for challenging intracranial aneurysms. The use of small devices of ≤3-mm diameter remains unapproved by major regulatory bodies. A retrospective review of patients treated with Pipeline Embolization Devices of ≤3-mm diameter at 3 Canadian institutions was conducted. Clinical and radiologic follow-up data were collected and reported. Twelve cases were treated with ≥1 Pipeline Embolization Device of ≤3-mm diameter, including 2 with adjunctive coiling, with a median follow-up of 18 months (range, 4-42 months). One patient experienced a posttreatment minor complication (8%) due to an embolic infarct. No posttreatment hemorrhage or delayed complications such as in-stent stenosis/thrombosis were observed. Radiologic occlusion was seen in 9/12 cases (75%) and near-occlusion in 2/12 cases (17%). Intracranial aneurysm treatment with small-diameter flow-diverting stents provided safe and effective aneurysm closure in this small selected sample. These devices should be further studied and considered for regulatory approval.

Effect of neighbourhood deprivation and social cohesion on mental health inequality: a multilevel population-based longitudinal study

BACKGROUND

The common mental disorders (CMDs) of anxiety and depression are the most common form of poor mental health in the general population. Evidence from the small number of previous cohort studies on the role of neighbourhood factors in mental health is inconclusive. We tested the hypothesis that high levels of neighbourhood social cohesion modify an adverse association between change in individual mental health and neighbourhood deprivation.

METHOD

We carried out a longitudinal multilevel analysis using data from the Caerphilly Health and Social Needs Cohort Study with a 7-year follow-up (n = 4426; age range 18-74 years at baseline). Neighbourhood deprivation and neighbourhood social cohesion were assessed at baseline and change in mental health between follow-up and baseline was assessed using the five-item Mental Health Inventory (MHI-5).

RESULTS

Residence in the most deprived neighbourhoods was negatively associated with change in mental health, after adjusting for baseline individual socio-economic risk factors and transitions in life events. This negative effect was significantly reduced in high social cohesion neighbourhoods. The predicted change in mental health score was calculated for the 10th and 90th centiles of the household low-income distribution. The difference between them was -2.8 in the low social cohesion group and 1.1 in the high cohesion group. The difference between the groups was 3.9 [95% confidence interval (CI) 0.2-7.6].

CONCLUSIONS

The public health burden of poor mental health and mental health inequality could potentially be reduced by strengthening social cohesion in deprived neighbourhoods. This offers a mechanism to address the adverse effect of neighbourhood deprivation on population mental health.

Can Multiple Mini Interviews work in an Irish setting? A feasibility study

Multiple Mini Interview (MMI) is a new selection tool for medical school applicants. Developed at McMaster University in 2004 it comprises a series of interview stations designed to measure performance across a range of competencies including communication skills, team work, and ethical reasoning. In September 2012, 109 First Year Medical students underwent the MMI. It consisted of 10 stations. The median total score, out of 150, was 100 (min 63, max 129). Cronbach Alphas for the 10 individual stations range from 0.74 to 0.80. Overall Cronbach Alpha of MMI items was 0.78. Staff and student feedback was positive. The outline cost per student was estimated at Euro 145. This study demonstrates that it is feasible to hold a MMI with acceptable levels of reliability and stakeholder approval in an Irish setting. Further work is ongoing to establish the concurrent and predictive validity of MMI in this cohort of medica students.

Cytokine Expression at Different Stages of Influenza A(H1N1)pdm09 Virus Infection in the Porcine Lung, Using Laser Capture Microdissection

Pandemic influenza A(H1N1)pdm09 virus has retained its ability to infect swine whilst developing the ability to transmit effectively between humans, thus making the pig a valuable model for studying disease pathogenesis in both species. Lung lesions in pigs caused by infection with influenza A viruses vary in both their severity and distribution with individual lung lobes exhibiting lesions at different stages of infection pathogenic development and disease resolution. Consequently, investigating interactions between the virus and host and their implications for disease pathogenesis can be complicated. Studies were undertaken to investigate the discrete expression of pro- and anti-inflammatory mediators during lung lesion formation in pigs during infection with influenza A(H1N1)pdm09 (A/Hamburg/05/09) virus. Laser capture microdissection was used to identify and select lung lobules containing lesions at different stages of development. Dissected samples were analysed using quantitative RT-PCR to assess pro- and anti-inflammatory cytokine mRNA transcripts. Differential expression of the immune mediators IL-8, IL-10 and IFN-γ was observed depending upon the lesion stage assessed. Upregulation of IFN-γ, IL-8 and IL-10 mRNA was observed in stage 2 lesions, whereas decreased mRNA expression was observed in stage 3 lesions, with IL-8 actively downregulated when compared with controls in both stage 3 and stage 4 lesions. This study highlighted the value of using laser capture microdissection to isolate specific tissue regions and investigate subtle differences in cytokine mRNA expression during lesion development in pigs infected with influenza A(H1N1)pdm09.

Compressive strength after blast of sandwich composite materials

Composite sandwich materials have yet to be widely adopted in the construction of naval vessels despite their excellent strength-to-weight ratio and low radar return. One barrier to their wider use is our limited understanding of their performance when subjected to air blast. This paper focuses on this problem and specifically the strength remaining after damage caused during an explosion. Carbon-fibre-reinforced polymer (CFRP) composite skins on a styrene-acrylonitrile (SAN) polymer closed-cell foam core are the primary composite system evaluated. Glass-fibre-reinforced polymer (GFRP) composite skins were also included for comparison in a comparable sandwich configuration. Full-scale blast experiments were conducted, where 1.6×1.3 m sized panels were subjected to blast of a Hopkinson-Cranz scaled distance of 3.02 m kg(-1/3), 100 kg TNT equivalent at a stand-off distance of 14 m. This explosive blast represents a surface blast threat, where the shockwave propagates in air towards the naval vessel. Hopkinson was the first to investigate the characteristics of this explosive air-blast pulse (Hopkinson 1948 Proc. R. Soc. Lond. A 89, 411-413 (doi:10.1098/rspa.1914.0008)). Further analysis is provided on the performance of the CFRP sandwich panel relative to the GFRP sandwich panel when subjected to blast loading through use of high-speed speckle strain mapping. After the blast events, the residual compressive load-bearing capacity is investigated experimentally, using appropriate loading conditions that an in-service vessel may have to sustain. Residual strength testing is well established for post-impact ballistic assessment, but there has been less research performed on the residual strength of sandwich composites after blast.

A marker-derived gene network reveals the regulatory role of PPARGC1A, HNF4G, and FOXP3 in intramuscular fat deposition of beef cattle

High intramuscular fat (IMF) awards price premiums to beef producers and is associated with meat quality and flavor. Studying gene interactions and pathways that affect IMF might unveil causative physiological mechanisms and inform genomic selection, leading to increased accuracy of predictions of breeding value. To study gene interactions and pathways, a gene network was derived from genetic markers associated with direct measures of IMF, other fat phenotypes, feedlot performance, and a number of meat quality traits relating to body conformation, development, and metabolism that might be plausibly expected to interact with IMF biology. Marker associations were inferred from genomewide association studies (GWAS) based on high density genotypes and 29 traits measured on 10,181 beef cattle animals from 3 breed types. For the network inference, SNP pairs were assessed according to the strength of the correlation between their additive association effects across the 29 traits. The co-association inferred network was formed by 2,434 genes connected by 28,283 edges. Topological network parameters suggested a highly cohesive network, in which the genes are strongly functionally interconnected. Pathway and network analyses pointed towards a trio of transcription factors (TF) as key regulators of carcass IMF: PPARGC1A, HNF4G, and FOXP3. Importantly, none of these genes would have been deemed as significantly associated with IMF from the GWAS. Instead, a total of 313 network genes show significant co-association with the 3 TF. These genes belong to a wide variety of biological functions, canonical pathways, and genetic networks linked to IMF-related phenotypes. In summary, our GWAS and network predictions are supported by the current literature and suggest a cooperative role for the 3 TF and other interacting genes including CAPN6, STC2, MAP2K4, EYA1, COPS5, XKR4, NR2E1, TOX, ATF1, ASPH, TGS1, and TTPA as modulators of carcass and meat quality traits in beef cattle.

Systematic review and meta-analysis of trainee- versus expert surgeon-performed colorectal resection

BACKGROUND

The aim of this meta-analysis was to compare short-term and oncological outcomes following colorectal resection performed by surgical trainees and expert surgeons.

METHODS

Systematic literature searches were made to identify articles on colorectal resection for benign or malignant disease published until April 2013. The primary outcome was the rate of anastomotic leak. Secondary outcomes were intraoperative variables, postoperative adverse event rates, and early and late oncological outcomes. Odds ratios (ORs), weighted mean differences (WMDs) and hazard ratios (HRs) for outcomes were calculated using meta-analytical techniques.

RESULTS

The final analysis included 19 non-randomized, observational studies of 14,344 colorectal resections, of which 8845 (61.7 per cent) were performed by experts and 5499 (38.3 per cent) by trainees. The overall rate of anastomotic leak was 2.6 per cent. Compared with experts, trainees had a lower leak rate (3.0 versus 2.0 per cent; OR 0.72, P = 0.010), but there was no difference between experts and expert-supervised trainees (3.2 versus 2.5 per cent; OR 0.77, P = 0.080). A subgroup of expert-supervised trainees had a significantly longer operating time for laparoscopic procedures (WMD 10.00 min, P < 0.001), lower 30-day mortality (OR 0.70, P = 0.001) and lower wound infection rate (OR 0.67, P = 0.040) than experts. No difference was observed in laparoscopic conversion, R0 resection or local recurrence rates. For oncological resection, there was no significant difference in cancer-specific survival between trainees and consultants (3 studies, 533 patients; hazard ratio 0.76, P = 0.130).

CONCLUSION

In selected patients, it is appropriate for supervised trainees to perform colorectal resection.

Performance of different SNP panels for parentage testing in two East Asian cattle breeds

The International Society for Animal Genetics (ISAG) proposed a panel of single nucleotide polymorphisms (SNPs) for parentage testing in cattle (a core panel of 100 SNPs and an additional list of 100 SNPs). However, markers specific to East Asian taurine cattle breeds were not included, and no information is available as to whether the ISAG panel performs adequately for these breeds. We tested ISAG's core (100 SNP) and full (200 SNP) panels on two East Asian taurine breeds: the Korean Hanwoo and the Japanese Wagyu, the latter from the Australian herd. Even though the power of exclusion was high at 0.99 for both ISAG panels, the core panel performed poorly with 3.01% false-positive assignments in the Hanwoo population and 3.57% in the Wagyu. The full ISAG panel identified all sire-offspring relations correctly in both populations with 0.02% of relations wrongly excluded in the Hanwoo population. Based on these results, we created and tested two population-specific marker panels: one for the Wagyu population, which showed no false-positive assignments with either 100 or 200 SNPs, and a second panel for the Hanwoo, which still had some false-positive assignments with 100 SNPs but no false positives using 200 SNPs. In conclusion, for parentage assignment in East Asian cattle breeds, only the full ISAG panel is adequate for parentage testing. If fewer markers should be used, it is advisable to use population-specific markers rather than the ISAG panel.

Propensity score analysis of oesophageal cancer treatment with surgery or definitive chemoradiotherapy

BACKGROUND

The role of treatments involving surgery versus definitive chemoradiotherapy (dCRT) for oesophageal cancer remains controversial.

METHODS

Consecutive patients with oesophageal cancer were studied. Those whose treatment involved surgery alone or who received neoadjuvant chemotherapy or chemoradiotherapy were compared with those receiving dCRT. Multiple regression models, including propensity scores, were developed to assess confounding factors associated with undergoing surgery or dCRT, and the risk-adjusted association between treatment and survival.

RESULTS

From a total of 727 patients, regression adjustment to control for bias created a cohort of 521 patients available for comparison (277 in the surgery group and 244 in the dCRT group). Local and distant recurrence rates were 10·1 and 22·0 per cent respectively after surgery, compared with 26·2 and 11·9 per cent following dCRT (P < 0·001). Median survival, and 2- and 5-year survival rates after surgery were 27 months, 53·8 and 31·0 per cent respectively, compared with 28 months, 54·2 and 31·9 per cent after dCRT (P = 0·918). On multivariable analysis, disease-free survival was related to endosonographic tumour category (hazard ratio (HR) 0·76, 95 per cent confidence interval 0·10 to 6·04 for T1; HR 1·57, 0·21 to 11·58 for T2; HR 2·12, 0·29 to 15·49 for T3; HR 3·07, 0·41 to 23·16 for T4; P = 0·003, in relation to T0 as reference), lymph node metastasis count (HR 1·10, 1·04 to 1·15; P < 0·001) and total disease length (HR 0·96, 0·93 to 1·00; P = 0·041).

CONCLUSION

There was no difference in survival after oesophageal cancer treatment involving surgery or dCRT.

Muscle specific miRNAs are induced by testosterone and independently upregulated by age

Age dependent decline in skeletal muscle function leads to impaired metabolic flexibility in elderly individuals. Physical activity and testosterone treatment have proven efficient strategies for delaying this condition. However, a common molecular pathway has not been identified. Muscle specific miRNAs (myomiRs) regulate metabolic pathways in skeletal muscle, are regulated by physical activity, and have response elements for testosterone in their promoter region. We therefore hypothesized that myomiRs would be regulated in skeletal muscle during aging. We further investigated any potential gender-dependent regulation of these miRNAs. We found that the myomiRs miR-1, miR-133a, and miR-133b were increased in skeletal muscle of elderly men compared to younger men. In addition, miR-133a/133b expression was markedly higher in women compared to men. Elimination of circulating testosterone in men was associated with lower levels of miR-133a and miR-133b. A positive regulatory effect of testosterone on miR-133a/133b expression was confirmed in castrated male C57BL/6J mice and in a model of primary human myocytes. Yet, an improvement of fitness level in the testosterone depleted men resulted in a down-regulation of miR133a/b. In conclusion, alterations in fitness level and circulating testosterone seem to represent two independent regulatory events where testosterone is a specific regulator of miR-133a/b expression.

Genome-wide association study for inhibin, luteinizing hormone, insulin-like growth factor 1, testicular size and semen traits in bovine species

The fertility of young bulls impacts on reproduction rates, farm profit and the rate of genetic progress in beef herds. Cattle researchers and industry therefore routinely collect data on the reproductive performance of bulls. Genome-wide association studies were carried out to identify genomic regions and genes associated with reproductive traits measured during the pubertal development of Tropical Composite bulls, from 4 to 24 months of age. Data from 1 085 bulls were collected for seven traits: blood hormone levels of inhibin at 4 months (IN), luteinizing hormone following a gonadotropin releasing hormone challenge at 4 months (LH), insulin-like growth factor 1 at 6 months (IGF1), scrotal circumference at 12 months (SC), sperm motility at 18 months (MOT), percentage of normal spermatozoa at 24 months (PNS) and age at a scrotal circumference of 26 cm (AGE26, or pubertal age). Data from 729 068 single-nucleotide polymorphisms were used in the association analysis. Significant polymorphism associations were discovered for IN, IGF1, SC, AGE26 and PNS. Based on these associations, INHBE, INHBC and HELB are proposed as candidate genes for IN regulation. Polymorphisms associated with IGF1 mapped to the PLAG1 gene region, validating a reported quantitative trait locus on chromosome 14 for IGF1. The X chromosome contained most of the significant associations found for SC, AGE26 and PNS. These findings will contribute to the identification of diagnostic genetic markers and informed genomic selection strategies to assist breeding of cattle with improved fertility. Furthermore, this work provides evidence contributing to gene function annotation in the context of male fertility.

The development of a family intervention competency assessment and reflection scale (FICARS) for psychosis

Family intervention (FI) for psychosis has a robust evidence base. In recommending its use the revised NICE schizophrenia guideline states 'Healthcare professionals providing psychological interventions should have an appropriate level of competence'. Yet, no definitive instrument exists to outline what competences are required during and post FI training or help recruit staff with the appropriate knowledge and skill. This paper reports on the development of a Family Intervention competency assessment and reflection scale (FICARS). Using a systematic three-staged approach commonly used in health outcomes measurement development, a comprehensive literature review on UK-based FI training and commonly used assessment tools was undertaken. A FICARS draft was then constructed and revised in consultation with expert FI clinicians. Finally, a content validity study with FI trainers and students across three FI training programmes was undertaken to optimize FICARS aim to promote reflective assessment and professional development in FI skills and practice.

Genome-wide association analyses for growth and feed efficiency traits in beef cattle

A genome-wide association study using the Illumina 50K BeadChip included 38,745 SNP on 29 BTA analyzed on 751 animals, including 33 purebreds and 718 crossbred cattle. Genotypes and 6 production traits: birth weight (BWT), weaning weight (WWT), ADG, DMI, midtest metabolic BW (MMWT), and residual feed intake (RFI), were used to estimate effects of individual SNP on the traits. At the genome-wide level false discovery rate (FDR < 10%), 41 and 5 SNP were found significantly associated with BWT and WWT, respectively. Thirty-three of them were located on BTA6. At a less stringent significance level (P < 0.001), 277 and 27 SNP were in association with single traits and multiple traits, respectively. Seventy-three SNP on BTA6 and were mostly associated with BW-related traits, and heavily located around 30 to 50Mb. Markers that significantly affected multiple traits appeared to impact them in same direction. In terms of the size of SNP effect, the significant SNP (P < 0.001) explained between 0.26 and 8.06% of the phenotypic variation in the traits. Pairs of traits with low genetic correlation, such as ADG vs. RFI or DMI vs. BWT, appeared to be controlled by 2 groups of SNP; 1 of them affected the traits in same direction, the other worked in opposite direction. This study provides useful information to further assist the identification of chromosome regions and subsequently genes affecting growth and feed efficiency traits in beef cattle.

Impact of antibiotics on the microcirculation in local and systemic inflammation

The main function of antibiotics is related to their capacity to eliminate a microorganism. In addition to the antimicrobial function of antibiotics, they are known to have anti-inflammatory and vasomodulatory effects on the microcirculation. The ability of non-antimicrobial derivatives of antibiotics to control inflammation illustrates the distinct anti-microbial and anti-inflammatory roles of antibiotics. In this review, we discuss the impact of antibiotics on leukocyte recruitment and the state of the microcirculation. Literature reporting the effect of antibiotics in non-infectious inflammatory conditions is reviewed as well as the studies demonstrating the anti-inflammatory effects of antibiotics in animal models of infection. In addition, the effect of the antibiotics on the immune system is summarized in this review, in order to postulate some mechanisms of action for the proand anti-inflammatory contribution of antibiotics. Literature reported the effect of antibiotics on the production of cytokines, chemotaxis and recruitment of leukocytes, production of reactive oxygen species, process of phagocytosis and autophagy, and apoptosis of leukocytes. Yet, all antibiotics may not necessarily exert an anti-inflammatory effect on the microcirculation. Thus, we suggest a model for spectrum of anti-inflammatory and vasomodulatory effects of antibiotics in the microcirculation of animals in local and systemic inflammation. Although the literature suggests the ability of antibiotics to modulate leukocyte recruitment and microperfusion, the process and the mechanism of action are not fully characterized. Studying this process will expand the knowledge base that is required for the selection of antibiotic treatment based on its anti-inflammatory functions, which might be particularly important for critically ill patients.

Parental patterns of use of over the counter analgesics in children

Over-The-Counter Analgesics (OTCA) account for over a fifth of Irish pharmacy sales. Little is known about patterns of use, specifically in children. This study investigated parents' use of OTCAs in children. A questionnaire exploring use of OTCAs and knowledge of side-effects was distributed to guardians of children attending three GP surgeries in South of Ireland from June-September 2010. The questionnaire was completed by 183 parents (response rate 95%). Many respondents (n = 121, 66.1%) were using analgesics when not required or using an inappropriate analgesic for a child's symptom. Private patients demonstrated better use (n = 31, 40%) than those with Medical Cards (n = 18, 22.5%) (p = 0.016). Identification of potential side-effects was poor, with drowsiness (n = 88, 49%), rash (n = 39, 22%) and nausea (n =3 2, 18%) listed as potential side-effects. Inappropriate use of OTCAs is prevalent in Irish children. Parents need more information and guidance on their use.

General practitioners' perspectives on revised entry and selection methods to medicine and the HPAT

Revised selection mechanisms to medicine now include an adjunct admission test known as the HPAT. Stakeholder acceptability is a key issue. General Practitioners (GPs) represent an important stakeholder group. A questionnaire was administered to a regional sample of GPs evaluating their knowledge of the new selection system, views on acceptability, performance on sample HPAT questions and perceptions of their relevance. 92 respondents (75.4%) reported they had little or no knowledge of the HPAT. GPs supported the use of aptitude tests (85 respondents 69.7%). However almost one third (39 respondents, 32%) either disagreed or strongly disagreed with the reforms introduced. The majority strongly supported the Leaving Certificate as a selection tool (118 respondents, 96.7%). GPs performed well in the sample questions. Items from Section 2, measuring interpersonal understanding, were judged to be the most relevant.

Detection of herpes viruses in the cerebrospinal fluid of adults with suspected viral meningitis in Malawi

PURPOSE

We looked for herpes simplex virus types 1 and 2 (HSV-1 and HSV-2, respectively), varicella zoster virus (VZV), Epstein-Barr virus (EBV) and cytomegalovirus (CMV) DNA in Malawian adults with clinically suspected meningitis.

METHODS

We collected cerebrospinal fluid (CSF) from consecutive adults admitted with clinically suspected meningitis to Queen Elizabeth Central Hospital (QECH), Blantyre, Malawi, for a period of 3 months. Those with proven bacterial or fungal meningitis were excluded. Real-time polymerase chain reaction (PCR) was performed on the CSF for HSV-1 and HSV-2, VZV, EBV and CMV DNA.

RESULTS

A total of 183 patients presented with clinically suspected meningitis. Of these, 59 (32 %) had proven meningitis (bacterial, tuberculous or cryptococcal), 39 (21 %) had normal CSF and 14 (8 %) had aseptic meningitis. For the latter group, a herpes virus was detected in 9 (64 %): 7 (50 %) had EBV and 2 (14 %) had CMV, all were human immunodeficiency virus (HIV)-positive. HSV-2 and VZV were not detected. Amongst those with a normal CSF, 8 (21 %) had a detectable herpes virus, of which 7 (88 %) were HIV-positive.

CONCLUSIONS

The spectrum of causes of herpes viral meningitis in this African population is different to that in Western industrialised settings, with EBV being frequently detected in the CSF. The significance of this needs further investigation.

Analgesic efficacy and safety of the novel p38 MAP kinase inhibitor, losmapimod, in patients with neuropathic pain following peripheral nerve injury: a double-blind, placebo-controlled study

BACKGROUND

Inhibitors of p38 mitogen-activated protein kinase are undergoing evaluation as a novel class of anti-rheumatic drugs, by virtue of their ability to suppress the production of pro-inflammatory cytokines. Emerging data suggests that they may also attenuate peripheral or central sensitization in neuropathic pain. A double-blind, placebo-controlled study was undertaken to evaluate the analgesic efficacy of losmapimod (GW856553), a novel p38α/β inhibitor, in subjects with neuropathic pain following traumatic peripheral nerve injury.

METHODS

One hundred and sixty-eight subjects with pain of at least moderate intensity (average daily score ≥4 on an 11-point pain intensity numeric rating scale; PI-NRS) at baseline were randomized to receive oral losmapimod, 7.5 mg BID or placebo for 28 days. Efficacy and safety assessments were undertaken at weekly clinic visits.

RESULTS

The mean treatment difference for the change in average daily pain score from baseline to week 4 of treatment based on the PI-NRS was -0.22 (95% CI -0.73, 0.28) in favour of losmapimod over placebo (p = 0.39). There were no statistically significant or clinically meaningful differences between the treatment groups over the 4-week dosing period for either the primary or secondary efficacy variables. There were no unexpected safety or tolerability findings following dosing with losmapimod.

CONCLUSIONS

Losmapimod could not be differentiated from placebo in terms of a primary analgesia response in patients with pain following peripheral nerve injury. The lack of response could reflect inadequate exposure at central sites of action or differences between rodent and human with respect to the target or neuropathic pain mechanisms.