The relationship between disease activity and UDCA response criteria in primary biliary cholangitis: A cohort study.

BACKGROUND: Uncertainty exists about how best to identify primary biliary cholangitis (PBC) patients who would benefit from second-line therapy. Existing, purely clinical, ursodeoxycholic acid (UDCA) response criteria accept degrees of liver biochemistry abnormality in responding patients, emerging data, however, suggest that any degree of ongoing abnormality may, in fact, be associated with an increased risk of adverse outcomes. This cohort study explores the link between response status, the biology of high-risk disease and its implications for clinical practice. METHODS: Proteomics, exploring 19 markers previously identified as remaining elevated in PBC following UDCA therapy, were performed on 400 serum samples, from participants previously recruited to the UK-PBC Nested Cohort between 2014 and 2019. All participants had an established diagnosis of PBC and were taking therapeutic doses of UDCA for greater than 12 months. UDCA response status was assessed using Paris 1, Paris 2 and the POISE criteria, with additional analyses using normal liver blood tests stratified by bilirubin level. Statistical analysis using parametric t tests and 1-way ANOVA. FINDINGS: Disease markers were statistically significantly higher in UDCA non-responders than in responders for all the UDCA response criteria, suggesting a meaningful link between biochemical disease status and disease mechanism. For each of the criteria, however, marker levels were also statistically significantly higher in responders with ongoing liver function test abnormality compared to those who had normalised their liver biochemistry. IL-4RA, IL-18-R1, CXCL11, 9 and 10, CD163 and ACE2 were consistently elevated across all responder groups with ongoing LFT abnormality. No statistically significant differences occurred between markers in normal LFT groups stratified by bilirubin level. INTERPRETATION: This study provides evidence that any ongoing elevation in alkaline phosphatase levels in PBC after UDCA therapy is associated with some degree of ongoing disease activity. There was no difference in activity between patients with normal LFT when stratified by bilirubin. These findings suggest that if our goal is to completely control disease activity in PBC, then normalisation of alkaline phosphatase and bilirubin should be the treatment target. This would also simplify messaging around goals of therapy in PBC, benefiting both patients and clinicians. FUNDING: Funding by the UK Medical Research Council (Stratified Medicine Programme) and an independent research grant by Pfizer. The study funders played no role in the study design, data collection, data analyses, data interpretation or manuscript writing.

Ameloblastic carcinoma in horses: case report and literature review.

Ameloblastic carcinoma is a malignant odontogenic neoplasm that has been reported only rarely in veterinary species. A 16-y-old Arabian crossbred mare was presented for evaluation of a hard mass on the body of the mandible, with evidence of osteolysis on radiographs. Incisional biopsies revealed an invasive neoplasm comprised of spindloid epithelial cells with a high mitotic count and partial dual cytokeratin-vimentin immunoreactivity. The horse was euthanized because of rapid tumor progression 3 mo after presentation. Postmortem evaluation revealed partial obliteration of the mandible by a large, firm-to-hard, tan, locally destructive and invasive mass with no gross or histologic evidence of metastasis. Postmortem histology revealed a poorly differentiated epithelial neoplasm with variably prominent features suggestive of odontogenic histogenesis: a plexiform ribbon architecture, infrequent basilar palisading with antibasilar nuclei, rare basilar cytoplasmic clearing, subepithelial matrix hyalinization, and partial dual cytokeratin-vimentin immunoreactivity. Features of malignancy included regions of necrosis, pronounced cellular atypia, a high mitotic count, extensive tissue invasion and local tissue destruction, and extension of neoplastic cells beyond the margins of the mandibular bone. Collectively, these features are most consistent with mandibular ameloblastic carcinoma. Including our case described here, ameloblastic carcinoma has been reported in only 5 horses. The microscopic features reported most consistently are dual cytokeratin-vimentin immunoreactivity, a high mitotic count, and basilar palisading. Ameloblastic carcinoma should be considered as a differential diagnosis for rapidly growing, locally invasive masses arising from the dentate jaw of horses.

Spatial Risk Factors for Pillar 1 COVID-19 Excess Cases and Mortality in Rural Eastern England, UK.

Understanding is still developing about spatial risk factors for COVID-19 infection or mortality. This is a secondary analysis of patient records in a confined area of eastern England, covering persons who tested positive for SARS-CoV-2 through end May 2020, including dates of death and residence area. We obtained residence area data on air quality, deprivation levels, care home bed capacity, age distribution, rurality, access to employment centers, and population density. We considered these covariates as risk factors for excess cases and excess deaths in the 28 days after confirmation of positive Covid status relative to the overall case load and death recorded for the study area as a whole. We used the conditional autoregressive Besag-York-Mollie model to investigate the spatial dependency of cases and deaths allowing for a Poisson error structure. Structural equation models were applied to clarify relationships between predictors and outcomes. Excess case counts or excess deaths were both predicted by the percentage of population age 65 years, care home bed capacity and less rurality: older population and more urban areas saw excess cases. Greater deprivation did not correlate with excess case counts but was significantly linked to higher mortality rates after infection. Neither excess cases nor excess deaths were predicted by population density, travel time to local employment centers, or air quality indicators. Only 66% of mortality was explained by locally high case counts. Higher deprivation clearly linked to higher COVID-19 mortality separate from wider community prevalence and other spatial risk factors.

The Serum Proteome and Ursodeoxycholic Acid Response in Primary Biliary Cholangitis.

BACKGROUND AND AIMS: Stratified therapy has entered clinical practice in primary biliary cholangitis (PBC), with routine use of second-line therapy in nonresponders to first-line therapy with ursodeoxycholic acid (UDCA). The mechanism for nonresponse to UDCA remains, however, unclear and we lack mechanistic serum markers. The UK-PBC study was established to explore the biological basis of UDCA nonresponse in PBC and identify markers to enhance treatment. APPROACH AND RESULTS: Discovery serum proteomics (Olink) with targeted multiplex validation were carried out in 526 subjects from the UK-PBC cohort and 97 healthy controls. In the discovery phase, untreated PBC patients (n = 68) exhibited an inflammatory proteome that is typically reduced in scale, but not resolved, with UDCA therapy (n = 416 treated patients). Nineteen proteins remained at a significant expression level (defined using stringent criteria) in UDCA-treated patients, six of them representing a tightly linked profile of chemokines (including CCL20, known to be released by biliary epithelial cells (BECs) undergoing senescence in PBC). All showed significant differential expression between UDCA responders and nonresponders in both the discovery and validation cohorts. A linear discriminant analysis, using serum levels of C-X-C motif chemokine ligand 11 and C-C motif chemokine ligand 20 as markers of responder status, indicated a high level of discrimination with an AUC of 0.91 (CI, 0.83-0.91). CONCLUSIONS: UDCA under-response in PBC is characterized by elevation of serum chemokines potentially related to cellular senescence and was previously shown to be released by BECs in PBC, suggesting a potential role in the pathogenesis of high-risk disease. These also have potential for development as biomarkers for identification of high-risk disease, and their clinical utility as biomarkers should be evaluated further in prospective studies.

Chronic bee paralysis as a serious emerging threat to honey bees.

Chronic bee paralysis is a well-defined viral disease of honey bees with a global distribution that until recently caused rare but severe symptomatology including colony loss. Anecdotal evidence indicates a recent increase in virus incidence in several countries, but no mention of concomitant disease. We use government honey bee health inspection records from England and Wales to test whether chronic bee paralysis is an emerging infectious disease and investigate the spatiotemporal patterns of disease. The number of chronic bee paralysis cases increased exponentially between 2007 and 2017, demonstrating chronic bee paralysis as an emergent disease. Disease is highly clustered spatially within most years, suggesting local spread, but not between years, suggesting disease burnt out with periodic reintroduction. Apiary and county level risk factors are confirmed to include scale of beekeeping operation and the history of honey bee imports. Our findings offer epidemiological insight into this damaging emerging disease.

A Bayesian approach to modelling the impact of hydrodynamic shear stress on biofilm deformation.

We investigate the feasibility of using a surrogate-based method to emulate the deformation and detachment behaviour of a biofilm in response to hydrodynamic shear stress. The influence of shear force, growth rate and viscoelastic parameters on the patterns of growth, structure and resulting shape of microbial biofilms was examined. We develop a statistical modelling approach to this problem, using combination of Bayesian Poisson regression and dynamic linear models for the emulation. We observe that the hydrodynamic shear force affects biofilm deformation in line with some literature. Sensitivity results also showed that the expected number of shear events, shear flow, yield coefficient for heterotrophic bacteria and extracellular polymeric substance (EPS) stiffness per unit EPS mass are the four principal mechanisms governing the bacteria detachment in this study. The sensitivity of the model parameters is temporally dynamic, emphasising the significance of conducting the sensitivity analysis across multiple time points. The surrogate models are shown to perform well, and produced ≈ 480 fold increase in computational efficiency. We conclude that a surrogate-based approach is effective, and resulting biofilm structure is determined primarily by a balance between bacteria growth, viscoelastic parameters and applied shear stress.

Extracellular Polymeric Substance Production and Aggregated Bacteria Colonization Influence the Competition of Microbes in Biofilms.

The production of extracellular polymeric substance (EPS) is important for the survival of biofilms. However, EPS production is costly for bacteria and the bacterial strains that produce EPS (EPS+) grow in the same environment as non-producers (EPS-) leading to competition between these strains for nutrients and space. The outcome of this competition is likely to be dependent on factors such as initial attachment, EPS production rate, ambient nutrient levels and quorum sensing. We use an Individual-based Model (IbM) to study the competition between EPS+ and EPS- strains by varying the nature of initial colonizers which can either be in the form of single cells or multicellular aggregates. The microbes with EPS+ characteristics obtain a competitive advantage if they initially colonize the surface as smaller aggregates and are widely spread-out between the cells of EPS-, when both are deposited on the substratum. Furthermore, the results show that quorum sensing-regulated EPS production may significantly reduce the fitness of EPS producers when they initially deposit as aggregates. The results provide insights into how the distribution of bacterial aggregates during initial colonization could be a deciding factor in the competition among different strains in biofilms.

A mechanistic Individual-based Model of microbial communities.

Accurate predictive modelling of the growth of microbial communities requires the credible representation of the interactions of biological, chemical and mechanical processes. However, although biological and chemical processes are represented in a number of Individual-based Models (IbMs) the interaction of growth and mechanics is limited. Conversely, there are mechanically sophisticated IbMs with only elementary biology and chemistry. This study focuses on addressing these limitations by developing a flexible IbM that can robustly combine the biological, chemical and physical processes that dictate the emergent properties of a wide range of bacterial communities. This IbM is developed by creating a microbiological adaptation of the open source Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). This innovation should provide the basis for "bottom up" prediction of the emergent behaviour of entire microbial systems. In the model presented here, bacterial growth, division, decay, mechanical contact among bacterial cells, and adhesion between the bacteria and extracellular polymeric substances are incorporated. In addition, fluid-bacteria interaction is implemented to simulate biofilm deformation and erosion. The model predicts that the surface morphology of biofilms becomes smoother with increased nutrient concentration, which agrees well with previous literature. In addition, the results show that increased shear rate results in smoother and more compact biofilms. The model can also predict shear rate dependent biofilm deformation, erosion, streamer formation and breakup.

Influence of increasing construct constraint in the presence of posterolateral deficiency at knee replacement: A biomechanical study.

When faced with posterolateral corner (PLC) deficiency, surgeons must choose a total knee replacement (TKR) construct that provides the appropriate level of constraint. This should match the internal constraint of the device to the soft tissue host laxity pattern. Little guidance is available peroperatively, with factors influencing final component choice remaining ill defined. This study aimed to quantify the effect of PLC insufficiency on the "envelope of laxity" (EoL) after TKR and the effect of increasingly component constraint upon knee behavior through a functional arc of flexion. Using computer navigation, mixed effect modeling and loaded cadaveric legs--laxity was quantified under separate states: the native knee, after implantation of a posterior stabilized (PS)-TKR, after sectioning the lateral (fibular) collateral ligament and popliteus tendon (PS-TKR-PLC), and after re-implantation with a semi-constrained "total stabilized" knee replacement (TS-TKR). Laxity was quantified from 0 to 110° of flexion for anterior draw, varus-valgus, and internal-external rotation. Implantation of the PS-TKR was consistently associated with increased constraint when compared to the native knee. PLC sectioning led to significantly increased laxity during varus stress from mid to deep flexion. Revision to a TS-TKR construct restored constraint mimicking that of the primary state but only for the arc of motion 0-90°. In a posterolateral deficient state, a fixed bearing semi-constrained TS-TKR restored the knee to near normal kinematics but this was only achieved from an arc of motion 0-90° of flexion. At higher flexion angles, there remained an unfavorable laxity pattern with varus stress opening.

How does laxity after single radius total knee arthroplasty compare with the native knee?

Patients with total knee arthroplasties (TKAs) continue to report dissatisfaction in functional outcome. Stability is a major factor contributing to functionality of TKAs. Implants with single-radius (SR) femoral components are proposed to increase stability throughout the arc of flexion. Using computer navigation and loaded cadaveric legs, we characterized the "envelope of laxity" (EoL) offered by a SR cruciate retaining (CR)-TKA compared with that of the native knee through the arc of flexion in terms of anterior drawer, varus/valgus stress, and internal/external rotation. In both the native knee and the TKA laxity increased with increasing knee flexion. Laxities measured in the three planes of motion were generally comparable between the native knee and TKA from 0° to 110° of flexion. Our results indicate that the SR CR-TKA offers appropriate stability in the absence of soft tissue deficiency.

DNA damage in horticultural farmers: a pilot study showing an association with organophosphate pesticide exposure.

A study of horticultural farmers exposed to organophosphate pesticides (OPs) and controls investigated the relationships between OP exposure, DNA damage and oxidative stress. Blood acetylcholinesterase (AChE) and urinary dialkylphosphate (DAP) levels determined exposure and 8-hydroxy-29- deoxyguanosine (8OHdG) indicated oxidative stress status. The farmers had approximately 30% lower AChE activity and increased DAP levels compared with the controls, reflecting moderate OP exposure. They had higher DNA damage than the controls and there was a significant positive relationship between DAP and DNA damage with greater than 95% power. The farmers also had a significant positive relationship between urinary DAP and 8OHdG levels.

Evaluation of immunocontraception as a publicly acceptable form of vertebrate pest species control: the introduced grey squirrel in Britain as an example.

We sent out a targeted questionnaire to organizations and private individuals across the UK that have expressed an interest in squirrel management and conservation. Respondents were asked to evaluate shooting, trapping, poisoning and immunocontraception (IMC), according to their perceived efficacy, cost efficiency, and whether they were considered to be humane. The majority of both professionals and enthusiasts indicated support for grey squirrel control to help conserve red squirrels and to reduce economic damage to timber crops. Respondents\' comparative evaluations of current forms of control showed that trapping is the most acceptable method. When IMC is compared with the other methods, it was considered to be more humane and acceptable. In contrast, poisoning was seen as humane or acceptable by the fewest respondents. Furthermore, poisoning elicited the greatest difference in opinion between the professional and enthusiast groups. This difference (34\%) may be interpreted partly as concern over the type of death that results from poisoning and partly as due to the possibility of poisoning nontarget species. Our findings indicate a need for more public information regarding secondary poisoning hazards to other species and their predators. Interest and concern about squirrel control correlated with the overlap between contemporary areas of distribution of the two species. It is these areas where consultation and education programs about control methods should be targeted. This research indicates that there would be support for grey squirrel control using IMC from both lay and professional interest groups. It demonstrates the existence of a sound basis for constructive dialog that can lead to the design and implementation of acceptable and efficient control strategies.