Whanau Maori and Pacific peoples' knowledge, perceptions, expectations and solutions regarding antibiotic treatment of upper respiratory tract infections: a qualitative study.

INTRODUCTION: The rate of community antibiotic use is high in Aotearoa New Zealand (NZ) when compared to other nations, and in NZ, as in most other nations, antibiotics are very commonly prescribed for self-limiting upper respiratory tract infections (URTIs). Resources that build knowledge, perceptions and understanding can potentially reduce unnecessary antibiotic consumption. METHODS: To inform the content of educational resources, we conducted an in-depth qualitative study with 47 participants via 6 focus groups of the knowledge, attitudes, and expectations of whanau Maori and Pacific peoples about antibiotics and URTIs. RESULTS: Focus groups with 47 participants identified four themes: Knowledge that might influence expectations to receive antibiotics for URTIs; Perceptions - the factors that influence when and why to seek medical care for URTI; Expectations - the features of successful medical care for URTI; Solutions - how to build community knowledge about URTI and their treatment and prevention. Knowledge that might reduce expectations to receive antibiotics for URTI included confidence in the use of alternative remedies, knowledge that URTI are usually caused by viruses, and concerns about antibiotic adverse effects. Participants commonly reported that they would confidently accept their doctor's recommendation that an antibiotic was not necessary for an URTI, provided that a thorough assessment had been performed and that treatment decisions were clearly communicated. CONCLUSION: These findings suggest that building patients' knowledge and skills about when antibiotics are necessary, and increasing doctors' confidence and willingness not to prescribe an antibiotic for patients with an URTI, could significantly reduce inappropriate antibiotic prescribing in NZ.

A Carbonic Anhydrase IX/SLC1A5 Axis Regulates Glutamine Metabolism Dependent Ferroptosis in Hypoxic Tumor Cells.

The ability of tumor cells to alter their metabolism to support survival and growth presents a challenge to effectively treat cancers. Carbonic anhydrase IX (CAIX) is a hypoxia-induced, metabolic enzyme that plays a crucial role in pH regulation in tumor cells. Recently, through a synthetic lethal screen, we identified CAIX to play an important role in redox homeostasis. In this study, we show that CAIX interacts with the glutamine (Gln) transporter, solute carrier family 1 member 5 (SLC1A5), and coordinately functions to maintain redox homeostasis through the glutathione/glutathione peroxidase 4 (GSH/GPX4) axis. Inhibition of CAIX increases Gln uptake by SLC1A5 and concomitantly increases GSH levels. The combined inhibition of CAIX activity and Gln metabolism or the GSH/GPX4 axis results in an increase in lipid peroxidation and induces ferroptosis, both in vitro and in vivo. Thus, this study demonstrates cotargeting of CAIX and Gln metabolism as a potential strategy to induce ferroptosis in tumor cells.

Cross-tissue immune cell analysis reveals tissue-specific features in humans.

Despite their crucial role in health and disease, our knowledge of immune cells within human tissues remains limited. We surveyed the immune compartment of 16 tissues from 12 adult donors by single-cell RNA sequencing and VDJ sequencing generating a dataset of ~360,000 cells. To systematically resolve immune cell heterogeneity across tissues, we developed CellTypist, a machine learning tool for rapid and precise cell type annotation. Using this approach, combined with detailed curation, we determined the tissue distribution of finely phenotyped immune cell types, revealing hitherto unappreciated tissue-specific features and clonal architecture of T and B cells. Our multitissue approach lays the foundation for identifying highly resolved immune cell types by leveraging a common reference dataset, tissue-integrated expression analysis, and antigen receptor sequencing.

Genome-wide association analysis for susceptibility to infection by Mycobacterium avium ssp. paratuberculosis in US Holsteins.

Paratuberculosis, or Johne's disease, is a chronic, granulomatous, gastrointestinal tract disease of cattle and other ruminants caused by the bacterium Mycobacterium avium subspecies paratuberculosis (MAP). Control of Johne's disease is based on programs of testing and culling animals positive for infection with MAP and concurrently modifying management to reduce the likelihood of infection. The current study was motivated by the hypothesis that genetic variation in host susceptibility to MAP infection can be dissected and quantifiable associations with genetic markers identified. Two separate GWAS analyses were conducted, the first using 897 genotyped Holstein artificial insemination sires with phenotypes derived from incidence of MAP infection among daughters based on milk ELISA testing records. The second GWAS analysis was a case-control design using US Holstein cows phenotyped for MAP infection by serum ELISA or fecal culture tests. Cases included cows positive for either serum ELISA, fecal culture, or both. Controls consisted of animals negative for all tests conducted. A total of 376 samples (70 cases and 306 controls) from a University of Minnesota Johne's management demonstration project and 184 samples (76 cases and 108 controls) from a Michigan State University study were used. Medium-density (sires) and high-density (cows) genotype data were imputed to full genome sequence for the analyses. Marker-trait associations were analyzed using the single-step (ss)GWAS procedure implemented in the BLUPF90 suite of programs. Evidence of significant genomic contributions for susceptibility to MAP infection were observed on multiple chromosomes. Results were combined across studies in a meta-analysis, and increased support for genomic regions on BTA7 and BTA21 were observed. Gene set enrichment analysis suggested pathways for antigen processing and presentation, antimicrobial peptides and natural killer cell-mediated cytotoxicity are relevant to variation in host susceptibility to MAP infection, among others. Genomic prediction was evaluated using a 5-fold cross-validation, and moderate correlations were observed between genomic breeding value predictions and daughter averages (∼0.43 to 0.53) for MAP infection in testing data sets. These results suggest that genomic selection against susceptibility to MAP infection is feasible in Holstein cattle.

Importing genetically altered animals: ensuring quality.

The reproducibility of research using laboratory animals requires reliable management of their quality, in particular of their genetics, health and environment, all of which contribute to their phenotypes. The point at which these biological materials are transferred between researchers is particularly sensitive, as it may result in a loss of integrity of the animals and/or their documentation. Here, we describe the various aspects of laboratory animal quality that should be confirmed when sharing rodent research models. We also discuss how repositories of biological materials support the scientific community to ensure the continuity of the quality of laboratory animals. Both the concept of quality and the role of repositories themselves extend to all exchanges of biological materials and all networks that support the sharing of these reagents.

Syntaxin4-Munc18c Interaction Promotes Breast Tumor Invasion and Metastasis by Regulating MT1-MMP Trafficking.

Invasion of neighboring extracellular matrix (ECM) by malignant tumor cells is a hallmark of metastatic progression. This invasion can be mediated by subcellular structures known as invadopodia, the function of which depends upon soluble N-ethylmaleimide-sensitive factor-activating protein receptor (SNARE)-mediated vesicular transport of cellular cargo. Recently, it has been shown the SNARE Syntaxin4 (Stx4) mediates trafficking of membrane type 1-matrix metalloproteinase (MT1-MMP) to invadopodia, and that Stx4 is regulated by Munc18c in this context. Here, it is observed that expression of a construct derived from the N-terminus of Stx4, which interferes with Stx4-Munc18c interaction, leads to perturbed trafficking of MT1-MMP, and reduced invadopodium-based invasion in vitro, in models of triple-negative breast cancer (TNBC). Expression of Stx4 N-terminus also led to increased survival and markedly reduced metastatic burden in multiple TNBC models in vivo. The findings are the first demonstration that disrupting Stx4-Munc18c interaction can dramatically alter metastatic progression in vivo, and suggest that this interaction warrants further investigation as a potential therapeutic target. IMPLICATIONS: Disrupting the interaction of Syntaxin4 and Munc18c may be a useful approach to perturb trafficking of MT1-MMP and reduce metastatic potential of breast cancers.

Genome-wide synthetic lethal screen unveils novel CAIX-NFS1/xCT axis as a targetable vulnerability in hypoxic solid tumors.

The metabolic mechanisms involved in the survival of tumor cells within the hypoxic niche remain unclear. We carried out a synthetic lethal CRISPR screen to identify survival mechanisms governed by the tumor hypoxia-induced pH regulator carbonic anhydrase IX (CAIX). We identified a redox homeostasis network containing the iron-sulfur cluster enzyme, NFS1. Depletion of NFS1 or blocking cyst(e)ine availability by inhibiting xCT, while targeting CAIX, enhanced ferroptosis and significantly inhibited tumor growth. Suppression of CAIX activity acidified intracellular pH, increased cellular reactive oxygen species accumulation, and induced susceptibility to alterations in iron homeostasis. Mechanistically, inhibiting bicarbonate production by CAIX or sodium-driven bicarbonate transport, while targeting xCT, decreased adenosine 5'-monophosphate-activated protein kinase activation and increased acetyl-coenzyme A carboxylase 1 activation. Thus, an alkaline intracellular pH plays a critical role in suppressing ferroptosis, a finding that may lead to the development of innovative therapeutic strategies for solid tumors to overcome hypoxia- and acidosis-mediated tumor progression and therapeutic resistance.

The use of continuous electronic prescribing data to infer trends in antimicrobial consumption and estimate the impact of stewardship interventions in hospitalized children.

BACKGROUND: Understanding antimicrobial consumption is essential to mitigate the development of antimicrobial resistance, yet robust data in children are sparse and methodologically limited. Electronic prescribing systems provide an important opportunity to analyse and report antimicrobial consumption in detail. OBJECTIVES: We investigated the value of electronic prescribing data from a tertiary children's hospital to report temporal trends in antimicrobial consumption in hospitalized children and compare commonly used metrics of antimicrobial consumption. METHODS: Daily measures of antimicrobial consumption [days of therapy (DOT) and DDDs] were derived from the electronic prescribing system between 2010 and 2018. Autoregressive moving-average models were used to infer trends and the estimates were compared with simulated point prevalence surveys (PPSs). RESULTS: More than 1.3 million antimicrobial administrations were analysed. There was significant daily and seasonal variation in overall consumption, which reduced annually by 1.77% (95% CI 0.50% to 3.02%). Relative consumption of meropenem decreased by 6.6% annually (95% CI -3.5% to 15.8%) following the expansion of the hospital antimicrobial stewardship programme. DOT and DDDs exhibited similar trends for most antimicrobials, though inconsistencies were observed where changes to dosage guidelines altered consumption calculation by DDDs, but not DOT. PPS simulations resulted in estimates of change over time, which converged on the model estimates, but with much less precision. CONCLUSIONS: Electronic prescribing systems offer significant opportunities to better understand and report antimicrobial consumption in children. This approach to modelling administration data overcomes the limitations of using interval data and dispensary data. It provides substantially more detailed inferences on prescribing patterns and the potential impact of stewardship interventions.

Overcoming Adaptive Resistance to KRAS and MEK Inhibitors by Co-targeting mTORC1/2 Complexes in Pancreatic Cancer.

Activating KRAS mutations are found in over 90% of pancreatic ductal adenocarcinomas (PDACs), yet KRAS has remained a difficult target to inhibit pharmacologically. Here, we demonstrate, using several human and mouse models of PDACs, rapid acquisition of tumor resistance in response to targeting KRAS or MEK, associated with integrin-linked kinase (ILK)-mediated increased phosphorylation of the mTORC2 component Rictor, and AKT. Although inhibition of mTORC1/2 results in a compensatory increase in ERK phosphorylation, combinatorial treatment of PDAC cells with either KRAS (G12C) or MEK inhibitors, together with mTORC1/2 inhibitors, results in synergistic cytotoxicity and cell death reflected by inhibition of pERK and pRictor/pAKT and of downstream regulators of protein synthesis and cell survival. Relative to single agents alone, this combination leads to durable inhibition of tumor growth and metastatic progression in vivo and increased survival. We have identified an effective combinatorial treatment strategy using clinically viable inhibitors, which can be applied to PDAC tumors with different KRAS mutations.

Ensilicated tetanus antigen retains immunogenicity: in vivo study and time-resolved SAXS characterization.

Our recently developed ensilication approach can physically stabilize proteins in silica without use of a pre-formed particle matrix. Stabilisation is done by tailor fitting individual proteins with a silica coat using a modified sol-gel process. Biopharmaceuticals, e.g. liquid-formulated vaccines with adjuvants, frequently have poor thermal stability; heating and/or freezing impairs their potency. As a result, there is an increase in the prevalence of vaccine-preventable diseases in low-income countries even when there are means to combat them. One of the root causes lies in the problematic vaccine 'cold chain' distribution. We believe that ensilication can improve vaccine availability by enabling transportation without refrigeration. Here, we show that ensilication stabilizes tetanus toxin C fragment (TTCF), a component of the tetanus toxoid present in the diphtheria, tetanus and pertussis (DTP) vaccine. Experimental in vivo immunization data show that the ensilicated material can be stored, transported at ambient temperatures, and even heat-treated without compromising the immunogenic properties of TTCF. To further our understanding of the ensilication process and its protective effect on proteins, we have also studied the formation of TTCF-silica nanoparticles via time-resolved Small Angle X-ray Scattering (SAXS). Our results reveal ensilication to be a staged diffusion-limited cluster aggregation (DLCA) type reaction. An early stage (tens of seconds) in which individual proteins are coated with silica is followed by a subsequent stage (several minutes) in which the protein-containing silica nanoparticles aggregate into larger clusters. Our results suggest that we could utilize this technology for vaccines, therapeutics or other biopharmaceuticals that are not compatible with lyophilization.

The effects of microchipping C57BL/6N mice on standard phenotyping tests.

The C57BL/6N inbred lines of mice are widely used in genetic research. They are particularly favoured in large scale studies such as the International Mouse Phenotyping Consortium (IMPC), where C57BL/6N mice are genetically altered to generate a collection of null alleles (currently more than 8500 null alleles have been generated). In this project, mice carrying null alleles are subjected to a pipeline of broad-based phenotyping tests to produce wide ranging phenotyping data on each model. We have previously described the development of a Home Cage Analysis system that automatically tracks the activity of group housed mice from a microchip inserted in the groin. This platform allows assessment of multiple biologically relevant phenotypes over long periods of time without experimenter interference, and therefore is particularly suited for high through-put studies. To investigate the impact of microchips on other tests carried out in the IMPC pipeline, we inserted microchips in 12 male and 12 female C57BL/6Ntac mice at seven weeks of age. Starting at nine weeks of age these mice underwent standard phenotyping tests, concurrently with 20 unchipped C57BL/6Ntac mice (10 females, 10 males). Tissues from a subset of the microchipped mice (six males and six females), chosen at random, were also sent for histopathological examination at the end of the phenotyping pipeline. No significant impact of insertion of microchip was observed in any of the phenotyping tests apart from bone mineral density measurement at DEXA due to the nature of the microchip. We therefore recommend that the microchip be inserted during the DEXA procedure, after the measurement is taken but before the mouse has recovered from the anaesthetic. This would avoid multiple anaesthetic exposures and prevent the potential variability in DEXA analysis output.

Use of a voluntary testing program to study the spatial epidemiology of Johne's disease affecting dairy herds in Minnesota: a cross sectional study.

BACKGROUND: One of the key steps in the management of chronic diseases in animals including Johne's disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP), is the ability to track disease incidence over space and time. JD surveillance in the U.S. dairy cattle is challenging due to lack of regulatory requirements, imperfect diagnostic tests, and associated expenses, including time and labor. An alternative approach is to use voluntary testing programs. Here, data from a voluntary JD testing program, conducted by the Minnesota Dairy Herd Improvement Association, were used to: a) explore whether such a program provides representative information on JD-prevalence in Minnesota dairy herds, b) estimate JD distribution, and, c) identify herd and environmental factors associated with finding JD-positive cows. Milk samples (n = 70,809) collected from 54,652 unique cows from 600 Minnesota dairy herds between November 2014 and April 2017 were tested using a MAP antibody ELISA. Participant representativeness was assessed by comparing the number of JD-tested herds with the number of herds required to estimate the true disease prevalence per county based on official statistics from the National Agricultural Statistical Services. Multivariable logistic regression models, with and without spatial dependence between observations, were then used to investigate the association between herd status to JD (positive/negative), as indicated by milk ELISA results, and available covariates at the herd level. RESULTS: Within the study population, at least one test-positive cow was found in 414 of 600 (69%) herds. Results indicated that large herds that test frequently and herds located in loamy or silt soils are more likely to have at least one MAP test-positive cow. After adjusting for herd size, testing frequency, and soil type, there was no spatial dependence in JD risk between neighboring dairies within 5 to 20 km. Furthermore, the importance of collecting data on herd management, feed, and biosecurity for insightful interpretations was recognized. The study suggested that, although limited, the voluntary testing database may support monitoring JD status. CONCLUSIONS: Results presented here help elucidate the spatial characteristics of JD in Minnesota and the study may ultimately contribute to the design and implementation of surveillance programs for the disease.

Salt bridge impact on global rigidity and thermostability in thermophilic citrate synthase.

It has been suggested that structural rigidity is connected to thermostability, e.g. in enzymes from thermophilic microorganisms. We examine the importance of correctly handling salt bridges, and interactions which we term 'strong polars', when constructing the constraint network for global rigidity analysis in these systems. Through a comparison of rigidity in citrate synthases, we clarify the relationship between rigidity and thermostability. In particular, with our corrected handling of strong polar interactions, the difference in rigidity between mesophilic and thermophilic structures is detected more clearly than in previous studies. The increase in rigidity did not detract from the functional flexibility of the active site in all systems once their respective temperature range had been reached. We then examine the distribution of salt bridges in thermophiles that were previously unaccounted for in flexibility studies. We show that in hyperthermophiles these have stabilising roles in the active site; occuring in close proximity to key residues involved in catalysis and binding of the protein.

Regulation of pH by Carbonic Anhydrase 9 Mediates Survival of Pancreatic Cancer Cells With Activated KRAS in Response to Hypoxia.

BACKGROUND & AIMS: Most pancreatic ductal adenocarcinomas (PDACs) express an activated form of KRAS, become hypoxic and dysplastic, and are refractory to chemo and radiation therapies. To survive in the hypoxic environment, PDAC cells upregulate enzymes and transporters involved in pH regulation, including the extracellular facing carbonic anhydrase 9 (CA9). We evaluated the effect of blocking CA9, in combination with administration of gemcitabine, in mouse models of pancreatic cancer. METHODS: We knocked down expression of KRAS in human (PK-8 and PK-1) PDAC cells with small hairpin RNAs. Human and mouse (KrasG12D/Pdx1-Cre/Tp53/RosaYFP) PDAC cells were incubated with inhibitors of MEK (trametinib) or extracellular signal-regulated kinase (ERK), and some cells were cultured under hypoxic conditions. We measured levels and stability of the hypoxia-inducible factor 1 subunit alpha (HIF1A), endothelial PAS domain 1 protein (EPAS1, also called HIF2A), CA9, solute carrier family 16 member 4 (SLC16A4, also called MCT4), and SLC2A1 (also called GLUT1) by immunoblot analyses. We analyzed intracellular pH (pHi) and extracellular metabolic flux. We knocked down expression of CA9 in PDAC cells, or inhibited CA9 with SLC-0111, incubated them with gemcitabine, and assessed pHi, metabolic flux, and cytotoxicity under normoxic and hypoxic conditions. Cells were also injected into either immune-compromised or immune-competent mice and growth of xenograft tumors was assessed. Tumor fragments derived from patients with PDAC were surgically ligated to the pancreas of mice and the growth of tumors was assessed. We performed tissue microarray analyses of 205 human PDAC samples to measure levels of CA9 and associated expression of genes that regulate hypoxia with outcomes of patients using the Cancer Genome Atlas database. RESULTS: Under hypoxic conditions, PDAC cells had increased levels of HIF1A and HIF2A, upregulated expression of CA9, and activated glycolysis. Knockdown of KRAS in PDAC cells, or incubation with trametinib, reduced the posttranscriptional stabilization of HIF1A and HIF2A, upregulation of CA9, pHi, and glycolysis in response to hypoxia. CA9 was expressed by 66% of PDAC samples analyzed; high expression of genes associated with metabolic adaptation to hypoxia, including CA9, correlated with significantly reduced survival times of patients. Knockdown or pharmacologic inhibition of CA9 in PDAC cells significantly reduced pHi in cells under hypoxic conditions, decreased gemcitabine-induced glycolysis, and increased their sensitivity to gemcitabine. PDAC cells with knockdown of CA9 formed smaller xenograft tumors in mice, and injection of gemcitabine inhibited tumor growth and significantly increased survival times of mice. In mice with xenograft tumors grown from human PDAC cells, oral administration of SLC-0111 and injection of gemcitabine increased intratumor acidosis and increased cell death. These tumors, and tumors grown from PDAC patient-derived tumor fragments, grew more slowly than xenograft tumors in mice given control agents, resulting in longer survival times. In KrasG12D/Pdx1-Cre/Tp53/RosaYFP genetically modified mice, oral administration of SLC-0111 and injection of gemcitabine reduced numbers of B cells in tumors. CONCLUSIONS: In response to hypoxia, PDAC cells that express activated KRAS increase expression of CA9, via stabilization of HIF1A and HIF2A, to regulate pH and glycolysis. Disruption of this pathway slows growth of PDAC xenograft tumors in mice and might be developed for treatment of pancreatic cancer.

Spleen Tyrosine Kinase-Mediated Autophagy Is Required for Epithelial-Mesenchymal Plasticity and Metastasis in Breast Cancer.

The ability of breast cancer cells to transiently transition between epithelial and mesenchymal states contributes to their metastatic potential. Therefore, driving tumor cells into a stable mesenchymal state, as opposed to complete tumor cell eradication, presents an opportunity to pharmacologically limit disease progression by promoting an asymptomatic state of dormancy. Here, we compare a reversible model of epithelial-mesenchymal transition (EMT) induced by TGFß to a stable mesenchymal phenotype induced by chronic exposure to the ErbB kinase inhibitor lapatinib. Only cells capable of returning to an epithelial phenotype resulted in skeletal metastasis. Gene expression analyses of the two mesenchymal states indicated similar transition expression profiles. A potently downregulated gene in both datasets was spleen tyrosine kinase (SYK). In contrast to this similar diminution in mRNA, kinome analyses using a peptide array and DNA-conjugated peptide substrates showed a robust increase in SYK activity upon TGFß-induced EMT only. SYK was present in cytoplasmic RNA processing depots known as P-bodies formed during the onset of EMT, and SYK activity was required for autophagy-mediated clearance of P-bodies during mesenchymal-epithelial transition (MET). Genetic knockout of autophagy-related 7 (ATG7) or pharmacologic inhibition of SYK activity with fostamatinib, a clinically approved inhibitor of SYK, prevented P-body clearance and MET, inhibiting metastatic tumor outgrowth. Overall, this study suggests assessment of SYK activity as a biomarker for metastatic disease and the use of fostamatinib as a means to stabilize the latency of disseminated tumor cells. SIGNIFICANCE: These findings present inhibition of spleen tyrosine kinase as a therapeutic option to limit breast cancer metastasis by promoting systemic tumor dormancy.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/8/1831/F1.large.jpg.See related commentary by Farrington and Narla, p. 1756.

Data Resource: Vascular Risk in Adult New Zealanders (VARIANZ) datasets.

INTRODUCTION: The Vascular Risk in Adult New Zealanders (VARIANZ) datasets contain a range of routinely-collected New Zealand health data relevant to cardiovascular disease (CVD) and related conditions. The datasets enable exploration of cardiovascular-related treatment, service utilisation, outcomes and prognosis. PROCESSES: Each dataset is constructed by anonymised individual-level linkage of eight national administrative health databases to identify all New Zealand adults aged ≥20 years who have recorded contact with publicly-funded New Zealand health services during a given year from 2006 onwards, when data quality is considered sufficient. DATA CONTENTS: Individual-level data for each VARIANZ dataset can include variables covering demography, dispensing of cardiovascular disease (CVD) preventive medications and prior hospitalisations for atherosclerotic CVD, heart failure, atrial fibrillation and diabetes. If required, VARIANZ datasets can be individually linked to follow-up national routinely collected health data in subsequent years, including all-cause mortality events and fatal/non-fatal CVD events, to create VARIANZ longitudinal cohorts. Bespoke linkage can also be undertaken to include other national and regional administrative health data such as non-CVD related hospitalisations in order to explore CVD comorbidities or novel risk factors. Furthermore, a subset of the VARIANZ datasets based on specific health contacts (such as CVD hospitalisations only) can also be identified, and some data can be requested for years prior to 2006. The New Zealand routinely-collected health databases used to construct the VARIANZ datasets do not capture primary care diagnostic classifications or certain CVD risk factor data such as smoking status, blood pressure or lipid profiles. CONCLUSION: The Vascular Risk in Adult New Zealanders (VARIANZ) datasets capture the majority of the New Zealand population in a given year and are available from 2006 onwards, or earlier than 2006 for some datasets based on specific health contacts. VARIANZ data can be used to explore a range of research questions regarding management, outcomes and prognosis for CVD.

Developing a risk management framework to improve public health outcomes by enumerating Salmonella in ground turkey.

Salmonella spp. continue to be a leading cause of foodborne morbidity worldwide. To assess the risk of foodborne disease, current national regulatory schemes focus on prevalence estimates of Salmonella and other pathogens. The role of pathogen quantification as a risk management measure and its impact on public health is not well understood. To address this information gap, a quantitative risk assessment model was developed to evaluate the impact of pathogen enumeration strategies on public health after consumption of contaminated ground turkey in the USA. Public health impact was evaluated by using several dose-response models for high- and low-virulent strains to account for potential under- or overestimation of human health impacts. The model predicted 2705-21 099 illnesses that would result in 93-727 reported cases of salmonellosis. Sensitivity analysis predicted cooking an unthawed product at home as the riskiest consumption scenario and microbial concentration the most influential input on the incidence of human illnesses. Model results indicated that removing ground turkey lots exceeding contamination levels of 1 MPN/g and 1 MPN in 25 g would decrease the median number of illnesses by 86-94% and 99%, respectively. For a single production lot, contamination levels higher than 1 MPN/g would be needed to result in a reported case to public health officials. At contamination levels of 10 MPN/g, there would be a 13% chance of detecting an outbreak, and at 100 MPN/g, the likelihood of detecting an outbreak increases to 41%. Based on these model prediction results, risk management strategies should incorporate pathogen enumeration. This would have a direct impact on illness incidence linking public health outcomes with measurable food safety objectives.

Material loss at the femoral head taper: a comparison study of the Exeter metal-on-polyethylene and contemporary metal-on-metal total hip arthroplasty.

AIMS: There are limited published data detailing the volumetric material loss from tapers of conventional metal-on-polyethylene (MoP) total hip arthroplasties (THAs). Our aim was to address this by comparing the taper wear rates measured in an explanted cohort of the widely used Exeter THA with those measured in a group of metal-on-metal (MoM) THAs. PATIENTS AND METHODS: We examined an existing retrieval database to identify all Exeter V40 and Universal MoP THAs. Volumetric wear analysis of the taper surfaces was conducted using previously validated methodology. These values were compared with those obtained from a series of MoM THAs using non-parametric statistical methodology. A number of patient and device variables were accounted for using multiple regression modelling. RESULTS: A total of 95 Exeter MoP and 249 MoM THAs were examined. The median volumetric loss from the MoM cohort was over four times larger than that from the MoP cohort (1.01 mm3 vs 0.23 mm3, p < 0.001), despite a significantly shorter median period in vivo for the MoM group (48 months vs 90 months, p < 0.001). Multiple regression modelling indicated that the dominant variables leading to greater female taper material loss were bearing diameter (p < 0.001), larger female taper angles (p < 0.001), and male titanium stem tapers (p < 0.001). CONCLUSION: Consistent with the long-term clinical success of the device, the volumetric material loss from Exeter femoral head tapers was, in general, small compared with that from larger-diameter MoM head tapers. Cite this article: Bone Joint J 2018;100-B:1310-9.

Knowledge gaps that hamper prevention and control of Mycobacterium avium subspecies paratuberculosis infection.

In the last decades, many regional and country-wide control programmes for Johne's disease (JD) were developed due to associated economic losses, or because of a possible association with Crohn's disease. These control programmes were often not successful, partly because management protocols were not followed, including the introduction of infected replacement cattle, because tests to identify infected animals were unreliable, and uptake by farmers was not high enough because of a perceived low return on investment. In the absence of a cure or effective commercial vaccines, control of JD is currently primarily based on herd management strategies to avoid infection of cattle and restrict within-farm and farm-to-farm transmission. Although JD control programmes have been implemented in most developed countries, lessons learned from JD prevention and control programmes are underreported. Also, JD control programmes are typically evaluated in a limited number of herds and the duration of the study is less than 5 year, making it difficult to adequately assess the efficacy of control programmes. In this manuscript, we identify the most important gaps in knowledge hampering JD prevention and control programmes, including vaccination and diagnostics. Secondly, we discuss directions that research should take to address those knowledge gaps.