The Impact of a Proprietary Blend of Yeast Cell Wall, Short-Chain Fatty Acids, and Zinc Proteinate on Growth, Nutrient Utilisation, and Endocrine Hormone Secretion in Intestinal Cell Models

In piglets, it is observed that early weaning can lead to poor weight gain due to an underdeveloped gastrointestinal (GI) tract, which is unsuitable for an efficient absorption of nutrients. Short-chain fatty acids (SCFAs) such as butyrate have demonstrated their ability to improve intestinal development by increasing cell proliferation, which is vital during this transition period when the small and large intestinal tracts are rapidly growing. Previous reports on butyrate inclusion in feed demonstrated significantly increased feed intakes (FIs) and average daily gains (ADGs) during piglet weaning. Similar benefits in piglet performance have been observed with the inclusion of yeast cell wall in diets. A proprietary mix of yeast cell wall, SCFAs, and zinc proteinate (YSM) was assessed here in vitro to determine its impact on cellular growth, metabolism and appetite-associated hormones in ex vivo small intestinal pig cells and STC-1 mouse intestinal neuroendocrine cells. Intestinal cells demonstrated greater cell densities with the addition of YSM (150 ppm) compared to the control and butyrate (150 ppm) at 24 h. This coincided with the higher utilisation of both protein and glucose from the media of intestinal cells receiving YSM. Ghrelin (an appetite-inducing hormone) demonstrated elevated levels in the YSM-treated cells on a protein and gene expression level compared to the cells receiving butyrate and the control, while satiety hormone peptide YY protein levels were lower in the cells receiving YSM compared to the control and butyrate-treated cells across each time point. Higher levels of ghrelin and lower PYY secretion in cells receiving YSM may drive the uptake of protein and glucose, which is potentially facilitated by elevated gene transporters for protein and glucose. Greater ghrelin levels observed with the inclusion of YSM may contribute to higher cell densities that could support pig performance to a greater extent than butyrate alone.

Differential impact of yeast cell wall products in recovery of porcine intestinal epithelial cell barrier function following Lipopolysaccharide challenge

BACKGROUND

In swine intestinal barrier deterioration can be caused by exposure to harmful bacteria, toxins or contaminants that can lead to a leaky gut and post weaning diarrhoea. A leaky gut leads to increased infection, inflammation and poor nutrient absorption that can impair piglet growth and ultimately survival. Application of yeast cell wall (YCW) products may offer an opportunity to reduce the intestinal barrier damage caused by microbial challenge. A Mannan rich fraction (MRF) and three YCW products were compared by examining their impact on intestinal barrier function using a Jejunal model of intestine in response to a bacterial challenge using Salmonella LPS.

RESULTS

Trans epithelial electrical resistance (TEER) readings showed MRF had a significantly higher barrier function (P ≤ 0.05) over the positive control while YCW products A, B and C demonstrated no significant improvement to the positive control. Transcriptome analysis of the IPEC-J2 cells showed that differentially expressed genes associated with the gene ontology (GO) term for Structural molecule activity was significantly upregulated in the MRF treated cells over the positive control cells with 56 genes upregulated compared to product B (50 genes), Product C, (25 genes) and the negative control's 60 genes. Product A had no functional grouping under the structural molecule activity term. Both qPCR and western blotting analysis of tight junction associated genes showed that MRF treated cells demonstrated significantly higher Claudin 3 junctional gene expression (P ≤ 0.05) over the positive control and treatments A, B and C. Occludin expression was significantly higher in MRF treated cells (P ≤ 0.05) over the positive control and product B. A nonsignificant rise in TJP-1 gene expression was observed in the MRF treated cells when compared to the positive control. Protein abundances of Claudin 3, Occludin and TJP-1 were significantly (P ≤ 0.05) higher following MRF application to LPS challenged IPEC-J2 cells over the positive control.

CONCLUSIONS

The difference in each YCW products production and composition appeared to influence intestinal barrier integrity. The action of MRF demonstrates its potential ability to raise intestinal barrier integrity of IPEC-J2 intestinal cells on an in vitro level through significantly elevated intracellular connections.

Hoof lesions in partly housed pasture-based dairy cows

Lameness is a symptom of a painful disorder affecting the limbs, which impacts dairy cow welfare and productivity. Lameness is primarily caused by hoof lesions. The prevalence of different lesion types can differ depending on environmental conditions and farm management practices. The aims of this observational study were to establish the cow-level and herd-level lesion prevalence during both housing and grazing periods in a partly housed, pasture-based system, establish the prevalence of lesions always associated with pain ("alarm" lesion), identify the lesions associated with a higher lameness score, determine relationships between lesions, and identify risk factors for digital dermatitis. On 98 farms during the grazing period and on 74 of the same farms during the housing period, every cow was lameness scored (0-3 lameness scoring scale), and the hind hooves of lame cows (score 2 and 3) were examined (maximum 20 cows per visit) and the prevalence of each lesion type recorded. To gather data on potential predictors for the risk factor analysis, a questionnaire with the farmer was conducted on lameness management practices and infrastructure measurements were taken at each visit. Cow-level data were also collected (e.g., parity, breed, milk yield, and so on). Noninfectious lesions were found to be more prevalent than infectious lesions in this system type. The most prevalent lesion types during both grazing and housing periods were white line separation, sole hemorrhages and overgrown claws; all remaining lesions had a cow-level prevalence of less than 15%. The cow-level prevalence of alarm lesions was 19% during the grazing period and 25% during the housing period; the most prevalent alarm lesion was sole ulcers during both periods. We found significantly more foreign bodies within the hoof sole (grazing = 14%, housing = 7%) and overgrown claws (grazing = 71%, housing = 55%) during the grazing period compared with the housing period. Cows with foul of the foot, sole ulcer, white line abscess, toe necrosis or an amputated claw had higher odds of being more severely lame, compared with mildly lame. The strongest correlation between lesions were between toe necrosis and digital dermatitis (r = 0.40), overgrown claws and corkscrew claws (r = 0.33), and interdigital hyperplasia and digital dermatitis (r = 0.31) at herd level. At the cow level, the strongest correlation was between overgrown claws and corkscrew claws (r = 0.27), and digital dermatitis and heel erosion (r = 0.22). The farmers' perception of the presence of digital dermatitis (and lameness) was significantly correlated with the actual presence of digital dermatitis recorded. Additional risk factors for the presence of digital dermatitis were cow track and verge width near the collecting yard, and stone presence on the cow tracks. Results from this study help further our understanding of the causes of lameness in partly housed, pasture-based dairy cows, and can be used to guide prevention and treatment protocols.

Risk factors associated with indicators of dairy cow welfare during the housing period in Irish, spring-calving, hybrid pasture-based systems

In a dairy production system where cows are grazing for a large portion of their lactation, little attention has been afforded to investigating multiple indicators of welfare for risk factors associated with the housing period. Yet regardless of the length of the housing period, cows still experience the positive and negative welfare impacts of both indoor and outdoor environments in a hybrid system. Thus, the objective of this study was to identify risk factors for indicators of dairy cow welfare during the housing period in a spring-calving, hybrid pasture-based system. Herd-level scores for seven indicators of welfare (locomotion, body condition, ocular and nasal discharge, integument damage, tail injury and human avoidance response) were collected from 82 Irish dairy farms during the housing period (October - February). Data were analysed using multiple beta regression or zero-inflated beta regression to identify associations between these welfare indicators and measured herd-level housing, resource and management factors. Thirty-six unique risk factors were associated with one or more welfare indicators (P < 0.05). Analyses identified two risk factors for body condition < 3.0 and four for body condition > 3.5, the target range during the housing period. Four risk factors were identified for each of ocular discharge, nasal discharge and avoidance response of > 1 m from human approach. Six risk factors each were associated with the proportion of lame cows and integument damage to the head-neck-back or hindquarter regions. The greatest number of risk factors, 12, were associated with tail injury (broken, lacerated or incomplete tails). Risk factors associated with multiple indicators of welfare were cow comfort index (tail lacerations and hindquarter integument damage), cubicle width (broken and incomplete tails), shed floor slipperiness (lameness and head-neck-back integument damage), shed light-level (tail lacerations, avoidance response and below target body condition), shed passage width (broken tails and head-neck-back integument damage) and presence (incomplete tails) or absence (broken tails) of a collecting yard backing gate. With the large number of risk factors associated with tail injury, continued research is necessary to identify causes and determine prevention methods to contribute to improved overall welfare of dairy cows. Housing features meeting recommended guidelines from the literature were frequently associated with greater negative indicators of welfare. In light of this, housing guidelines may benefit from regular re-evaluation to ensure facilities meet the welfare needs of cows during the housing period.

Lameness prevalence and management practices on Irish pasture-based dairy farms

Background

Lameness is a painful disease, which negatively impacts dairy cow production and welfare. The aim of this observational study was to determine herd lameness prevalence, describe current lameness management practices and identify the presence of established risk factors for lameness on Irish pasture-based dairy farms. Farms were visited once during grazing (99 farms) and again during housing (85 farms). Lameness scoring was carried out at each visit (AHDB 0–3 scale); cows were classified as lame if they scored two or three. Farm management practices and infrastructure characteristics were evaluated via farmer questionnaires and direct measurements of farm infrastructure.

Results

Median herd-level lameness prevalence was 7.9% (interquartile range = 5.6 – 13.0) during grazing and 9.1% (interquartile range = 4.9 – 12.0) during housing; 10.9% of cows were lame at a single visit and 3.5% were lame at both visits (chronically lame or had a repeat episode of lameness). Fifty-seven percent of farmers were not familiar with lameness scoring and only one farm carried out lameness scoring. Only 22% of farmers kept records of lame cows detected, and 15% had a lameness herd health plan. Twenty-eight percent of farmers waited more than 48 h to treat a lame cow, and 21% waited for more than one cow to be identified as lame before treating. Six percent of farmers carried out routine trimming and 31% regularly footbathed (> 12 times per year). Twelve percent put severely lame cows in a closer paddock and 8% stated that they used pain relief to treat severely lame cows. Over 50% of farms had at least one cow track measurement that was classified as rough or very rough, and cow tracks were commonly narrow for the herd size. On 6% of farms, all cubicle beds were bare concrete (no matting or bedding) and on a further 6% of farms, there was a combination of cubicles with and without matting or bedding. On 56% of farms, all pens contained less than 1.1 cubicles per cow and on 28% of farms, a proportion of pens contained less than 1.1 cubicles per cow.

Conclusions

Overall, this study identified infrastructure and management practices which could be improved upon. The comparatively low lameness prevalence demonstrated, compared to fully housed systems, also highlights the benefits of a pasture-based system for animal welfare; however, there remains scope for improvement.

Cow- and herd-level risk factors for lameness in partly housed pasture-based dairy cows

Lameness in dairy cows is a major animal welfare concern and has substantial economic impact through reduced production and fertility. Previous risk factor analyses have focused on housed systems, rather than those where cows were grazed for the majority of the year and housed only for the winter period. Therefore, the aim of this observational study was to identify a robust set of cow-level and herd-level risk factors for lameness in a pasture-based system, based on predictors from the housing and grazing periods. Ninety-nine farms were visited during the grazing period (April 2019-September 2019), and 85 farms were revisited during the housing period (October 2019-February 2020). At each visit, all lactating cows were scored for lameness (0 = good mobility, 1 = imperfect mobility, 2 = impaired mobility, 3 = severely impaired mobility), and potential herd-level risk factors were recorded through questionnaires and infrastructure measurements. Routine cow-level management data were also collected. Important risk factors for lameness were derived though triangulation of results from elastic net regression, and from logistic regression model selection using modified Bayesian information criterion. Both selection methods were implemented using bootstrapping. This novel approach has not previously been used in a cow-level or herd-level risk factor analysis in dairy cows, to the authors' knowledge. The binary outcome variable was lameness status, whereby cows with a lameness score of 0 or 1 were classed as non-lame and cows with a score of 2 or 3 were classed as lame. Cow-level risk factors for increased lameness prevalence were age and genetic predicted transmitting ability for lameness. Herd-level risk factors included farm and herd size, stones in paddock gateways, slats on cow tracks near the collecting yard, a sharper turn at the parlor exit, presence of digital dermatitis on the farm, and the farmers' perception of whether lameness was a problem on the farm. This large-scale study identified the most important associations between risk factors and lameness, based on the entire year (grazing and housing periods), providing a focus for future randomized clinical trials.

PSIX-21 Assessment of barrier function and cell junctional expression on differentiated intestinal porcine epithelial cells in response to Salmonella LPS challenge and treatment with Yeast cell wall products

Mannan rich fractions were previously demonstrated to improve junctional gene expression which can reduce leaky intestinal tracts that facilitate bacterial infection in piglets. The work here assessed MRF and other yeast mannan products’ effects on intestinal barrier function in response to bacterial challenge from Salmonella LPS. Differentiated IPEC cells were grown to 14 days until a trans-epithelial electrical resistance reading (TEER) of ~ 4500 Ohms/cm2 was reached. Prior to lipopolysaccharide (LPS) (1µg/mL) challenge, cells were pre-treated and post-treated with MRF or yeast products A, B, and C (16mg/mL). Post treated cells were lysed in RLT buffer and RNA isolated (RNeasy). RIN values above 7 were used to synthesise cDNA (SuperScript®-III). Junctional genes Occludin, Claudin3 and Tight junction protein1 (TJP1) were assessed by qPCR (Applied Biosystems 7500 Fast). TNFα proinflammatory secretion was measured by ELISA. Three independent biological replicates were performed, with One-way ANOVA carried out unless stated otherwise. TEER results showed MRF significantly recovered barrier function (5090.3±187.0, P ≤ 0.05) over the positive control (PC) (3754.2±605.8) while product A (3502.5±182.7749), B (3414.289±733.8854) and C (3938.4±491.4) demonstrated no significant improvement to the PC. MRF treated cells were significantly higher for Claudin3 gene expression (1.33±0.18, P ≤ 0.05) over the control (0.671661±0.277) and treatments A (0.53±0.16, P ≤ 0.05), B (0.91±0.18, P ≤ 0.05) and C (0.69±0.25, P ≤ 0.05). Occludin expression was significantly higher in MRF treated cells (1.09±0.01, P ≤ 0.05) over the PC (0.89±0.09, P ≤ 0.05) and treatment B (0.88±0.04, P ≤ 0.05). TJP-1 gene expression was highest in the MRF treated cells (1.30±0.41) but not significantly, compared to the PC (1.00±0.14). TNFα (pg/mL) protein secretion was significantly lower in both the MRF treated (0.0809±0.86x10-3, P ≤ 0.05) and treatment C 0.081±0.18 x10-3, P ≤ 0.05) over the PC (0.0813±0.22x10-3). MRF augmented junctional expression improving TEER readings and potentially lessened LPS intracellular leakage that led to lower proinflammatory protein secretion. The present study highlights differences in efficacy of a variety of yeast cell wall products.

Altered Degranulation and pH of Neutrophil Phagosomes Impacts Antimicrobial Efficiency in Cystic Fibrosis

Studies have endeavored to understand the cause for impaired antimicrobial killing by neutrophils of people with cystic fibrosis (PWCF). The aim of this study was to focus on the bacterial phagosome. Possible alterations in degranulation of cytoplasmic granules and changes in pH were assessed. Circulating neutrophils were purified from PWCF (n = 28), PWCF receiving ivacaftor therapy (n = 10), and healthy controls (n = 28). Degranulation was assessed by Western blot analysis and flow cytometry. The pH of phagosomes was determined by use of BCECF-AM-labelled Staphylococcus aureus or SNARF labelled Candida albicans. The antibacterial effect of all treatments tested was determined by colony forming units enumeration. Bacterial killing by CF and healthy control neutrophils were found to differ (p = 0.0006). By use of flow cytometry and subcellular fractionation the kinetics of intraphagosomal degranulation were found to be significantly altered in CF phagosomes, as demonstrated by increased primary granule CD63 (p = 0.0001) and myeloperoxidase (MPO) content (p = 0.03). In contrast, decreased secondary and tertiary granule CD66b (p = 0.002) and decreased hCAP-18 and MMP-9 (p = 0.02), were observed. After 8 min phagocytosis the pH in phagosomes of neutrophils of PWCF was significantly elevated (p = 0.0001), and the percentage of viable bacteria was significantly increased compared to HC (p = 0.002). Results demonstrate that the recorded alterations in phagosomal pH generate suboptimal conditions for MPO related peroxidase, and α-defensin and azurocidine enzymatic killing of Staphylococcus aureus and Pseudomonas aeruginosa. The pattern of dysregulated MPO degranulation (p = 0.02) and prolonged phagosomal alkalinization in CF neutrophils were normalized in vivo following treatment with the ion channel potentiator ivacaftor (p = 0.04). Our results confirm that alterations of circulating neutrophils from PWCF are corrected by CFTR modulator therapy, and raise a question related to possible delayed proton channel activity in CF.

PSIII-18 Assessment of Salmonella Dublin infection of intestinal porcine epithelial cells (IPEC) in response to Zinc Oxide and a Yeast Mannan Rich Fraction

Salmonella species are associated with post-weaning diarrhea, which results in poor weight gain, potential death, and economic cost. A yeast mannan rich fraction (MRF) was assessed alongside the industry standard treatment Zinc Oxide (ZO) in vitro to determine its impact on Salmonella Dublin infection of a pig intestinal cell line (IPEC). IPEC cells were exposed to MRF or ZO in the presence of S. Dublin (1x108/mL). IPEC cell RNA was isolated and cDNA synthesized. Gene expression for IL-1β, TNFα, IL-8 and cellular tight Junction genes Occludin, Claudin3 and Tight junction protein1 (TJP1) were assessed by qPCR. S. Dublin adhesion to IPEC cells (500:1) assessed in the presence or absence of either ZO or MRF for 1 hour at 37°C. IPEC cells with attached S. Dublin were lysed, diluted, plated and incubated overnight and enumeration. Three biological replicates were performed for all experiments and statistical analysis determined by One-way ANOVA. Proinflammatory gene TNFα was significantly reduced (P ≤ 0.001) following S. Dublin infection and treatment with MRF compared with ZO. IL-1β demonstrated no change between treatments although IL-8 gene expression was significantly reduced in both ZO (P≤0.01) and MRF (P ≤ 0.05) treated cells over the control. Significantly higher expression of Occludin (P ≤ 0.01), Claudin3 (P ≤ 0.001) and TJP1 (P ≤ 0.05) was observed in IPEC cells exposed to S. Dublin in the presence of MRF compared to ZO. Adhesion of S. Dublin to IPEC cells was significantly reduced in response to MRF addition compared to ZO treated cells (P ≤ 0.001) and the control cells (P ≤ 0.05). ZO treated cell demonstrated no improvement over the control cell levels of bacterial attachment. Both on a physical and molecular level bacterial infection of intestinal cells was more significantly impaired by MRF addition. With the ban on ZO, yeast MRF may prove to be a suitable alternative to support gut health in piglets.

Activation of complement component 3 is associated with airways disease and pulmonary emphysema in alpha-1 antitrypsin deficiency

INTRODUCTION

Alpha-1 antitrypsin (AAT) deficiency (AATD) is associated with early onset emphysema. The aim of this study was to investigate whether AAT binding to plasma constituents could regulate their activation, and in AATD, exploit this binding event to better understand the condition and uncover novel biomarkers of therapeutic efficacy.

METHODS

To isolate AAT linker proteins, plasma samples were separated by size exclusion chromatography, followed by co-immunoprecipitation. AAT binding proteins were identified by mass spectrometry. Complement turnover and activation was determined by ELISA measurement of C3, C3a and C3d levels in plasma of healthy controls (n=15), AATD (n=51), non-AATD patients with obstructive airway disease (n=10) and AATD patients post AAT augmentation therapy (n=5).

RESULTS

Direct binding of complement C3 to AAT was identified in vivo and in vitro. Compared with healthy controls, a breakdown product of C3, C3d, was increased in AATD (0.04 µg/mL vs 1.96 µg/mL, p=0.0002), with a significant correlation between radiographic pulmonary emphysema and plasma levels of C3d (R²=0.37, p=0.001). In vivo, AAT augmentation therapy significantly reduced plasma levels of C3d in comparison to patients not receiving AAT therapy (0.15 µg/mL vs 2.18 µg/mL, respectively, p=0.001).

DISCUSSION

Results highlight the immune-modulatory impact of AAT on the complement system, involving an important potential role for complement activation in disease pathogenesis in AATD. The association between plasma C3d levels and pulmonary disease severity, that decrease in response to AAT augmentation therapy, supports the exploration of C3d as a candidate biomarker of therapeutic efficacy in AATD.

Elastic distortion determining conduction in BiFeO3 phase boundaries

It is now well-established that boundaries separating tetragonal-like (T) and rhombohedral-like (R) phases in BiFeO₃ thin films can show enhanced electrical conductivity. However, the origin of this conductivity remains elusive. Here, we study mixed-phase BiFeO₃ thin films, where local populations of T and R can be readily altered using stress and electric fields. We observe that phase boundary electrical conductivity in regions which have undergone stress-writing is significantly greater than in the virgin microstructure. We use high-end electron microscopy techniques to identify key differences between the R–T boundaries present in stress-written and as-grown microstructures, to gain a better understanding of the mechanism responsible for electrical conduction. We find that point defects (and associated mixed valence states) are present in both electrically conducting and non-conducting regions; crucially, in both cases, the spatial distribution of defects is relatively homogeneous: there is no evidence of phase boundary defect aggregation. Atomic resolution imaging reveals that the only significant difference between non-conducting and conducting boundaries is the elastic distortion evident – detailed analysis of localised crystallography shows that the strain accommodation across the R–T boundaries is much more extensive in stress-written than in as-grown microstructures; this has a substantial effect on the straightening of local bonds within regions seen to electrically conduct. This work therefore offers distinct evidence that the elastic distortion is more important than point defect accumulation in determining the phase boundary conduction properties in mixed-phase BiFeO₃.

The localized crystallography of conducting and non-conducting phase boundaries in mixed-phase BiFeO₃ is directly compared using scanning transmission electron microscopy techniques.

Correction: Giant resistive switching in mixed phase BiFeO3via phase population control

Correction for 'Giant resistive switching in mixed phase BiFeO₃via phase population control' by David Edwards et al., Nanoscale, 2018, 10, 17629-17637.

Giant resistive switching in mixed phase BiFeO3via phase population control

Highly-strained coherent interfaces, between rhombohedral-like (R) and tetragonal-like (T) phases in BiFeO3 thin films, often show enhanced electrical conductivity in comparison to non-interfacial regions. In principle, changing the population and distribution of these interfaces should therefore allow different resistance states to be created. However, doing this controllably has been challenging to date. Here, we show that local thin film phase microstructures (and hence R-T interface densities) can be changed in a thermodynamically predictable way (predictions made using atomistic simulations) by applying different combinations of mechanical stress and electric field. We use both pressure and electric field to reversibly generate metastable changes in microstructure that result in very large changes of resistance of up to 108%, comparable to those seen in Tunnelling Electro-Resistance (TER) devices.

"Fat is really a four-letter word": Exploring weight-related communication best practices in children with and without disabilities and their caregivers

BACKGROUND

Health care professionals play a critical role in preventing and managing childhood obesity, but the American Academy of Pediatrics recently stressed the importance of using sensitive and nonstigmatizing language when discussing weight with children and families. Although barriers to weight-related discussions are well known, there are few evidence-based recommendations around communication best practices. Disability populations in particular have previously been excluded from work in this area. The objectives were to present the findings of a recent scoping review to children with and without disabilities and their caregivers for their reactions; and to explore the experiences and perceptions of the children and their caregivers regarding weight-related communication best practices.

METHODS

Focus group and individual interviews were conducted with 7-18-year olds with and without disabilities and their caregivers. The interview guide was created using findings from a recent scoping review of weight-related communication best practices. Inductive thematic analysis was employed.

RESULTS

Eighteen children (9 boys; 7 children with disabilities) and 21 caregivers (17 mothers, 1 step-father, 3 other caregivers) participated in 8 focus group and 7 individual interviews. Preferred communication strategies were similar across those with and without disabilities, although caregivers of children with autism spectrum disorder endorsed more concrete approaches. Discussions emphasizing growth and health were preferred over weight and size. Strengths-based, solution-focused approaches for weight conversations were endorsed, although had not been widely experienced.

CONCLUSION

Perceptions of weight-related communication were similar across stakeholder groups, regardless of children's disability or weight status. Participants generally agreed with the scoping review recommendations, suggesting that they apply broadly across different settings and populations; however, tailoring them to specific circumstances is critical. Empirical evaluations are still required to examine the influence of weight-related communication on clinically important outcomes, including behaviour change and family engagement in care.

In-vivo evaluation of the response of Galleria mellonella larvae to novel copper(II) phenanthroline-phenazine complexes

Herein we report the in-vivo characterisation and metabolic changes in Galleria mellonella larvae to a series of bis-chelate copper(II) phenanthroline-phenazine cationic complexes of [Cu(phen)₂]²⁺ (Cu-Phen), [Cu(DPQ)(Phen)]²⁺ (Cu-DPQ-Phen) and [Cu(DPPZ)(Phen)]²⁺ (Cu-DPPZ-Phen) (where phen = 1,10-phenanthroline, DPQ = dipyrido[3,2-ƒ:2',3'-h]quinoxaline and DPPZ = dipyrido[3,2-a:2',3'-c]phenazine). Our aim was to investigate the influence of the systematic extension of the ligated phenazine ligand in the G. mellonella model as a first step towards assessing the in-vivo tolerance and mode of action of the complex series with respect to the well-studied oxidative chemical nuclease, Cu-Phen. The Lethal Dose₅₀ (LD₅₀) values were established over dose ranges of 2 - 30 μg at 4-, 24-, 48- and 72 h by mortality assessment, with Cu-Phen eliciting the highest mortality at 4 h (Cu-Phen, 12.62 μg < Cu-DPQ-Phen, 21.53 μg < Cu-DPPZ-Phen, 26.07 μg). At other timepoints, a similar profile was observed as the phenazine π-backbone within the complex scaffold was extended. Assessment of both cellular response and related gene expression demonstrated that the complexes did not initiate an immune response. However, Label-Free Quantification proteomic data indicated the larval response was associated with upregulation of key proteins such as Glutathione S-transferase, purine synthesis and glycolysis/gluconeogenesis (e.g. fructose-bisphosphate aldolase and glyceraldehyde-3-phosphate). Both Cu-Phen and Cu-DPQ-Phen elicited a similar in-vivo response in contrast to Cu-DPPZ-Phen, which displayed a substantial increase in nitrogen detoxification proteins and proteins with calcium binding sites. Overall, the response of G. mellonella larvae exposure to the complex series is dominated by detoxification and metabolic proteome response mechanisms.

Barriers to and enablers of healthy lifestyle behaviours in adolescents with obesity: a scoping review and stakeholder consultation

Healthy lifestyle behaviours are key to successful weight management, but have proven to be challenging to attain for adolescents with obesity. The purpose of our scoping review was to (i) describe barriers and enablers that adolescents with obesity encounter for healthy nutrition, physical activity, sedentary behaviour and sleep habits and (ii) identify gaps in the literature. We adhered to established methodology for scoping reviews. Six databases were searched (1980-June 2016) for original articles published in English or French that focused on lifestyle behaviours of 13- to 17-year-olds in paediatric weight management. Following screening and data extraction, findings of selected articles were synthesized thematically using a social ecological framework. Stakeholder consultation (n = 20) with adolescents with obesity and health professionals was completed to enhance methodological rigour. Our search yielded 17 articles for inclusion, including 546 unique participants. Barriers to healthy nutrition and physical activity were more consistently related to individual-level and interpersonal-level factors; enablers tended to be linked with interpersonal-level factors. Knowledge gaps identified related to sedentary behaviour and sleep as well as environmental and policy levels of influence. Our review revealed that some barriers and enablers were unique to adolescents with obesity, which were either within or beyond their control. These findings highlight the importance of multilevel interventions to enable healthy lifestyle behaviours for weight management.

Animal Models of Cystic Fibrosis Pathology: Phenotypic Parallels and Divergences

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The resultant characteristic ion transport defect results in decreased mucociliary clearance, bacterial colonisation, and chronic neutrophil-dominated inflammation. Much knowledge surrounding the pathophysiology of the disease has been gained through the generation of animal models, despite inherent limitations in each. The failure of certain mouse models to recapitulate the phenotypic manifestations of human disease has initiated the generation of larger animals in which to study CF, including the pig and the ferret. This review will summarise the basic phenotypes of three animal models and describe the contributions of such animal studies to our current understanding of CF.

Galleria mellonella as a host model to study Aspergillus terreus virulence and amphotericin B resistance

The aim of this study was to investigate if the alternative in vivo model Galleria mellonella can be used (i) to determine differences in pathogenicity of amphotericin B (AMB) resistant and susceptible A. terreus isolates, (ii) to evaluate AMB efficacy in vivo (iii) and to correlate outcome to in vitro susceptibility data. Larvae were infected with 2 A. terreus AMB resistant (ATR) and 3 AMB susceptible (ATS) isolates and survival rates were correlated to physiological attributes and killing ability of larval haemocytes. Additionally, infected larvae were treated with different concentrations of L-AMB. Haemocyte density were ascertained to evaluate the influence of L-AMB on the larval immune cells. Larvae were sensitive to A. terreus infection in an inoculum-size and temperature dependent manner. In vitro susceptibility to L-AMB correlated with in vivo outcome of antifungal treatment, defining an AMB susceptible strain cluster of A. terreus. Susceptibility to L-AMB increased virulence potential in the larval model, but this increase was also in accordance with faster growth and less damage caused by larval haemocytes. L-AMB treatment primed the larval immune response by increasing haemocyte density. G. mellonella provides a convenient model for the in vivo screening of A. terreus virulence and treatment options, contributing to the generation of a hypothesis that can be further tested in refined experiments in mammalian models.

Prolonged pre-incubation increases the susceptibility of Galleria mellonella larvae to bacterial and fungal infection

Galleria mellonella larvae are widely used for assessing the virulence of microbial pathogens and for measuring the in vivo activity of antimicrobial agents and produce results comparable to those that can be obtained using mammals. The aim of the work described here was to ascertain the effect of pre-incubation at 15°C for 1, 3, 6 or 10 weeks on the susceptibility of larvae to infection with Candida albicans and Staphylococcus aureus. Larvae infected with C. albicans after 1 week pre-incubation at 15°C showed 73.3 ± 3.3% survival at 24 hours post-infection while those infected after 10 weeks pre-incubation showed 30 ± 3.3% survival (P < 0.01). Larvae infected with S. aureus after 1 week pre-incubation showed 65.5 ± 3.3% survival after 24 hours while those infected after 10 weeks pre-incubation showed 13.3 ± 3.3% (P < 0.001). Analysis of the haemocyte density in larvae pre-incubated for 3-10 weeks showed a reduction in haemocytes over time but a proportionate increase in the density of granular haemocytes in the population as determined by FACS analysis. Proteomic analysis revealed decreased abundance of proteins associated with metabolic pathways (e.g. malate dehydrogenase, fructose-1,6-bisphosphatase, glyceraldehyde-3-phosphate dehydrogenase) and prophenoloxidase. G. mellonella larvae are a useful in vivo model system but the duration of the pre-incubation stage significantly affects their susceptibility to microbial pathogens possibly as a result of altered metabolism.

Thermal and physical stresses induce a short-term immune priming effect in Galleria mellonella larvae

Exposure of larvae of Galleria mellonella larvae to mild physical (i.e. shaking) or thermal stress for 24h increased their ability to survive infection with Aspergillus fumigatus conidia however larvae stressed in a similar manner but incubated for 72h prior to infection showed no elevation in their resistance to infection with A. fumigatus. Stressed larvae demonstrated an elevated haemocyte density 24h after initiation of the stress event but this declined at 48 and 72h. Larval proteins such as apolipophorin, arylophorin and prophenoloxidase demonstrated elevated expression at 24h but not at 72h. Larvae maintained at 37°C showed increased expression of a range of antimicrobial and immune-related proteins at 24h but these decreased in expression thereafter. The results presented here indicate that G. mellonella larvae are capable of altering their immune response following exposure to mild thermal or physical stress to mount a response capable of counteracting microbial infection which reaches a peak 24h after the initiation of the priming event and then declines by 72h. A short-term immune priming effect may serve to prevent infection but maintaining an immune priming effect for longer periods may be metabolically costly and unnecessary while living within the colony of another insect.

An analysis of the structural and functional similarities of insect hemocytes and mammalian phagocytes

The insect immune response demonstrates a number of structural and functional similarities to the innate immune system of mammals. As a result of these conserved features insects have become popular choices for evaluating the virulence of microbial pathogens or for assessing the efficacy of antimicrobial agents and give results which are comparable to those that can be obtained using mammals. Analysis of the cellular component of the insect and mammalian immune systems demonstrates many similarities. Insect hemocytes recognize pathogens and phagocytose material in a similar manner to neutrophils. The killing of ingested microbes is achieved in both cell types by the production of superoxide and by the release of enzymes in the process of degranulation. Insect hemocytes and mammalian neutrophils are sensitive to the same inhibitors. This review highlights the strong similarities between the phagocytic cells of both groups of animals and demonstrates the potential benefits of using selected insects as in vivo screening systems.

Effect of nutrient deprivation on the susceptibility of Galleria mellonella larvae to infection

Larvae of Galleria mellonella are widely used to study the virulence of microbial pathogens and for assessing the potency of antimicrobial agents. This work examined the effect of nutritional deprivation on the ability of larvae to withstand infection in order to establish standardized conditions for the treatment of larvae for in vivo testing. Larvae deprived of food for seven days demonstrated an increased susceptibility to infection by the yeast Candida albicans. These larvae displayed a lower density of hemocytes compared with controls but hemocytes from starved and control larvae demonstrated the same ability to kill yeast cells. Hemolymph from starved larvae demonstrated reduced expression of a range of antimicrobial peptides (e.g., lipocalin) and immune proteins (e.g., apolipophorin and arylphorin). Deprivation of G. mellonella larvae of food leads to a reduction in the cellular and immune responses and an increased susceptibility to infection. Researchers utilizing these larvae should ensure adequate food is provided to larvae in order to allow valid comparisons to be made between results from different laboratories.

Acid stress in the food pathogen Bacillus cereus

AIMS

The pathogen Bacillus cereus, which is associated with a number of foods including dairy products, was studied for its response to acid stress during the exponential phase.

METHODS AND RESULTS

Bacillus cereus was found to adapt to acid stress (pH 4.6) when pre-exposed to a non-lethal, inducing pH of 6.3 or to inducing concentrations of heat, ethanol, salt or hydrogen peroxide. Cells were found to maintain their internal pH at a higher level than the external acid pH and adapted cells had a higher internal pH than unadapted cells. A constitutive acid-sensitive mutant that was also heat- and ethanol-sensitive was found to be capable of high levels of adaptation despite its lack of induction of proteins induced in the wild type by exposure to moderate pH (6.3) values.

CONCLUSIONS

A number of proteins were found to be underexpressed in the mutant compared with the wild type at pH 6.3, including some with homology to ribosomal proteins and to the sporulation regulator RapK, while one differentially expressed band contained two proteins, one of which was homologous to the competence regulator CodY.

SIGNIFICANCE AND IMPACT OF THE STUDY

The work has implications for the processing of B. cereus-associated foods by acidification. The linked developmental processes of stationary phase, sporulation and possibly competence appear to be involved in the response to acid stress.

Heat and salt stress in the food pathogen Bacillus cereus

AIMS

The effects of stresses imposed on bacterial contaminants during food processing and treatment of packaging material were evaluated on the food pathogen Bacillus cereus.

METHODS AND RESULTS

Conditions were established which allowed the cells to adapt to heat, ethanol and hydrogen peroxide stresses, but not to osmotic shock. Cross protection between stresses indicated a clear hierarchy of resistance with salt protecting against hydrogen peroxide, which protected against ethanol, which protected against heat shock. The cultures were shown to be most sensitive to heat, ethanol and oxidative stress at mid-exponential phase and to become resistant at stationary phase. Adaptive levels of stressor were found to induce synthesis of general stress and stress-specific proteins and differential accumulation of proteins was demonstrated between heat- or salt-stressed and unstressed cells.

CONCLUSIONS

Sequencing revealed that a number of glycolytic enzymes were regulated by heat and osmotic shocks and that the chaperone GroEL was induced by heat shock.

SIGNIFICANCE AND IMPACT OF THE STUDY

The implications of the physiological data in designing storage and processing conditions for food are discussed. The identification of stress-regulated proteins reveals a clear role for glycolysis in adaptation to heat shock and osmotic stress.

Violence and its injury consequences in American movies: a public health perspective

OBJECTIVES

To evaluate the seriousness and frequency of violence and the degree of associated injury depicted in the 100 top-grossing American films of 1994.

METHODS

Each scene in each film was examined for the presentation of violent actions on persons and coded by a systematic context-sensitive analytic scheme. Specific degrees of violence and indices of injury severity were abstracted. Only actually depicted, not implied, actions were coded, although both explicit and implied consequences were examined.

RESULTS

The median number of violent actions per film was 16 (range, 0-110). Intentional violence outnumbered unintentional violence by a factor of 10. Almost 90% of violent actions showed no consequences to the recipient's body, although more than 80% of the violent actions were executed with lethal or moderate force. Fewer than 1% of violent actions were accompanied by injuries that were then medically attended.

CONCLUSIONS

Violent force in American films of 1994 was overwhelmingly intentional and in 4 of 5 cases was executed at levels likely to cause significant bodily injury. Not only action films but movies of all genres contained scenes in which the intensity of the action was not matched by correspondingly severe injury consequences. Many American films, regardless of genre, tend to minimize the consequences of violence to human beings.

Violence and its injury consequences in American movies: a public health perspective

OBJECTIVES

The purpose of this study was to evaluate the seriousness and frequency of violence and the degree of associated injury depicted in the 100 top grossing American films of 1994.

METHODS

Each scene in each film was examined for the presentation of violent actions upon persons and coded by means of a systematic context sensitive analytic scheme. Specific degrees of violence and indices of injury severity were abstracted. Only actually depicted, not implied, actions were coded, although both explicit and implied consequences were examined.

RESULTS

The median number of violent actions per film was 16, with a range from 1 to 110. Intentional violence outnumbered unintentional violence by a factor of 10. Almost 90% of violent actions showed no consequences to the recipient's body, although more than 80% of the violent actions were executed with lethal or moderate force. Fewer than 1% of violent actions were accompanied by injuries that were then medically attended.

CONCLUSIONS

Violent force in American films of 1994 was overwhelmingly intentional and in four of five cases was executed at levels likely to cause significant bodily injury. Not only action films but movies of all genres contained scenes in which the intensity of the action was not matched by correspondingly severe injury consequences. Many American films, regardless of genre, tend to minimize the consequences of violence to human beings.

Characterization and acute phase modulation of canine apolipoprotein H (beta 2-glycoprotein I)

Apolipoprotein H (ApoH) is a 50 kDa glycoprotein capable of binding to negatively charged phospholipids and is a probable inhibitor of the blood coagulation pathway, platelet aggregation, and platelet prothrombinase activity, as well as being involved in autoimmune disease. We have cloned and sequenced a full length ApoH cDNA clone from a beagle dog liver library. Its derived amino acid sequence shows high cross-species similarity to ApoH from other mammals. Canine ApoH mRNA expression is down regulated during an experimentally induced inflammatory response establishing that it is a negative acute phase reactant.

Positive charges at the NH2 terminus convert the membrane-anchor signal peptide of cytochrome P-450 to a secretory signal peptide

The NH2-terminal sequences of cytochromes P-450 resemble signal peptides, but these sequences are not cleaved during the insertion of these integral membrane proteins into the microsomes. To examine whether these putative signal peptides are functionally equivalent to signal peptides of secretory proteins, cDNA coding for a fusion protein was produced, in which the signal peptide for preproparathyroid hormone was replaced with the putative signal peptide of cytochrome P450IIC2. The translational product of RNA synthesized in vitro from the cDNA was neither processed nor translocated by chicken oviduct microsomal membranes in a reticulocyte cell-free system but was resistant to extraction from the membranes by alkaline solutions. In addition, the translation of the hybrid RNA was arrested by signal recognition particle. Unlike most signal peptides, the cytochrome P450IIC2 NH2-terminal sequence does not contain basic amino acids preceding the hydrophobic core. Introduction by oligonucleotide-directed mutagenesis of lysine and arginine at the NH2 terminus resulted in a fusion protein that was partially processed by the microsomal membranes, with translocation across the membrane of both the processed and unprocessed proteins. The positive charges convert the cytochrome P450IIC2 NH2 terminus from a combination membrane insertion-halt transfer signal to a more classical secretory membrane-insertion signal, possibly by altering the orientation of the signal peptide in the membrane.

Non-medical services for the hard of hearing and deaf in newfoundland and labrador

The hard of hearing communicate mainly by speech, the deaf by sign language. Services differ, but some hearing-impaired persons need non-medical services provided for both groups. These services are important in Newfoundland because there are few hearing-health professionals to serve a small population distributed over a wide area. This article outlines problems faced by the hard of hearing and describes the services provided by the Newfoundland Hearing Association, the Newfoundland School for the Deaf, the Parents' Association of the Deaf, and the Counselling/Interpreting services of the Newfoundland Co-ordinating Council on Deafness. Programs need to be expanded, but are suggested as an appropriate model for any area of the country.

Evidence that rabbit cytochrome P-450 K is encoded by the plasmid pP-450 PBc2

The complete coding sequence for P-450 PBc2 was inserted into a T7-phage promoter system, and a capped cRNA was generated using T7 RNA polymerase. The P-450 PBc2 cRNA was translated in a rabbit reticulocyte lysate. The in vitro translation product was indirectly immunoprecipitated by the monoclonal antibodies 2F5 and 3C3 that recognize P-450 K. SDS-polyacrylamide gel electrophoresis revealed that the translated protein product exhibits the same relative electrophoretic mobility as P-450 K. The N-terminal amino acid sequence was determined to be MDLVVVLGL-LS-LLLLSL- for P-450 K immunopurified from rabbit kidney using the monoclonal antibody 2F5. This sequence agrees with the predicted amino acid sequence derived from the P-450 PBc2 cDNA. These results indicate that P-450 K or a protein closely related to P-450 K is encoded by the plasmid pP-450 PBc2.

Chromosome 3 duplication q21 leads to qter deletion p25 leads to pter syndrome in children of carriers of a pericentric inversion inv(3) (p25q21)

Close phenotypic similarity between two cases carrying a rec(3) dup q,inv(3) (p25q21), 12 additional infants from the same inv (3)(p25q21) kindred who lived less than 1 year, and eight cases studied in other medical centers has led us to postulate the existence of a distinct chromosome 3 duplication-deletion syndrome. In the presence of trisomy for (3)q21 leads to qter and monosomy for (3)p25 leads to pter, the facial dysmorphy is unique: a distorted head shape due to irregular cranial sutures, thick low eyebrows, long eyelashes, persistent lanugo, distended veins on the scalp, hypertelorism, oblique palpebral fissures, a very short nose with a broad depressed bridge and anteverted nares, protruding maxilla, thin upper lip, micrognathia, low-set ears, and a short webbed neck. Port-wine stains, congenital glaucoma, cloudy corneas, cleft palate and harelip also occur frequently. Each infant has difficulty sucking and swallowing. Congenital anomalies of the cardiovascular system, of midgut rotation, and of the urogenital system are noted for the infants who died neonatally. Most frequent is a ventricular septal defect, followed by atrial septal defect, patent ductus arteriosus, patent foramen ovale, and coarctation of the aorta. Omphalocele, umbilical hernia, hyperplastic kidneys, polycystic kidneys, double ureter, hydro-ureter, hydronephrosis, and undescended testes often occur. The extremities are short in proportion to the length of the trunk. Clinodactyly, coxa valga, talipes, and spina bifida are frequently observed.