Palliative psychiatry: research, clinical, and educational priorities

BACKGROUND

Palliative psychiatry has been proposed as a new clinical construct within mental health care and aims to improve quality of life (QoL) for individuals experiencing severe and persistent mental illness (SPMI). To date, explorations of palliative psychiatry have been largely theoretical, and more work is needed to develop its approaches into tangible clinical practice.

METHODS

In this paper, we synthesize existing literature with discussions held at a one-day knowledge user meeting titled "A Community of Practice for Palliative Psychiatry" to generate priorities for research, clinical practice, and education that will help advance the development of palliative psychiatry.

RESULTS

Palliative psychiatry will benefit from research that is co-produced by people with lived experience (PWLE) of mental illness, that clarifies contested concepts within mental health care and wider medicine, and that adapts existing interventions that have the potential to improve the QoL of individuals experiencing SPMI into the mental health care context. Specific methods and tools might be developed for use in clinical spaces taking a palliative psychiatry approach. More work must be done to understand the populations that might benefit from palliative psychiatry, and to mitigate mental health care providers' (MHCPs') anxieties about using these approaches in their work. As palliative psychiatry is developed, current MHCPs, trainees, individuals experiencing SPMI, and their loved ones will all require education about and orientation to this novel approach within mental health care.

CONCLUSIONS

There are several priorities in research, clinical practice, and education that can help advance the development of palliative psychiatry. All future work must be considered through a human rights-based, anti-oppressive lens. Research projects, clinical models, and educational initiatives should all be developed in co-production with PWLE to mitigate the epistemic injustices common in mental health care.

South African Institute of Drug-Free Sport Position Statement on CBD (Cannabidiol) and THC (Tetrahydrocannabinol)

Cannabidiol (CBD) and Tetrahydrocannabinol (THC) have become easily available to athletes over the years. Using these substances may inadvertently expose an athlete to the possibility of an adverse analytical finding (a "positive" test) and a sanction. Athletes need to understand the risk of an anti-doping rule violation or adverse analytical finding should these products be used, especially if no therapeutic use exemption exists. This position statement attempts to clarify the use of CBD and THC and their associated risks with Anti-Doping Rule Violations (ADRV) in the athletic population. The South African Sports Medicine Association supports this position statement.

The Impact of the COVID-19 Pandemic on Creutzfeldt-Jakob Disease Surveillance and Patient Care in the United Kingdom

Background and purpose

Creutzfeldt–Jakob disease (CJD) is lethal and transmissible. We assessed the impact of the COVID‐19 pandemic on UK CJD surveillance. We hypothesized that (i) disruptions prolonged diagnostic latency; (ii) autopsy rates declined; and (iii) COVID‐19 infection negatively affected diagnosis, care, and survival.

Methods

We retrospectively investigated the first year of the pandemic, using the preceding year as a comparator, quantifying numbers of individuals assessed by the UK National CJD Research & Surveillance Unit for suspected CJD, time to diagnosis, disease duration, and autopsy rates. We evaluated the impact of COVID‐19 status on diagnosis, care, and survival in CJD.

Results

A total of 148 individuals were diagnosed with CJD in the pandemic (from a total of 166 individuals assessed) compared to 141 in the comparator (from 145 assessed). No differences were identified in disease duration or time to diagnosis. Autopsy rates were unchanged. Twenty individuals had COVID‐19; 60% were symptomatic, and 10% had severe disease. Disruptions in diagnosis and care were frequently identified. Forty percent of COVID‐19‐positive individuals died; however, COVID‐19 status did not significantly alter survival duration in CJD.

Conclusions

The COVID‐19 pandemic has not impacted UK CJD case ascertainment or survival, but diagnostic evaluation and clinical care of individuals have been affected.

An Ethics-Informed, Comparative Analysis of Uterus Transplantation and Gestational Surrogacy for Uterine Factor Infertility in High-Income Countries

Interest in the future, clinical implementation of uterus transplantation for uterine factor infertility was recently boosted by the demonstration of proof-of-concept for deceased uterus donation/transplantation. The ethical dimensions of living and deceased uterus transplantation are explored and addressed in the paper through their comparison to the ethical elements of an existing, legal, assisted reproduction practice in some high-income countries, i.e., gestational surrogacy. A set of six ethics lenses is used in the comparative analysis: reproductive autonomy and rights, informed choice/consent, relevant critical relational theories, health equity, theoretical application of the accepted living donation standard, and comparative benefits and burdens considerations. Gestational surrogacy, as currently practiced in some high-income countries, is the assumed, theoretical base-threshold for determination of ethical acceptability in assisted reproduction practices. The analysis demonstrates that (at the present time): 1) the ethical acceptability of living uterus donation/transplantation is less than that of gestational surrogacy in high-income countries, and 2) the ethical acceptability of deceased uterus donation/transplantation is roughly equivalent to that of gestational surrogacy. This leads to the conclusion that, at the present time, only one version of uterus transplantation practice, i.e., deceased uterus transplantation, should be considered ethically acceptable for possible clinical implementation in high-income countries.

Should Institutional Conscientious Objection to Assisted Dying be Accommodated?

The contentious, topical debate about whether faith-based health care organizations should be granted accommodation on the basis of institutional conscientious objection to medical assistance is dying (MAiD) is addressed through a comparative analysis of arguments on both sides of the issue that references such relevant considerations as: claimed ‘moral-authority’, competing rights-based claims, obligations arising from patient welfare principles, formal justice, dissimilarity in consequences, and two illustrative arguments from analogy. The analysis leads to the conclusion that nonconditional accommodation on the basis of institutional conscientious objection to MAiD is not ethically acceptable in Canada. A compromise mechanism, consisting of a suggested set of pragmatic conditions, is proposed that could effectively balance the competing moral responsibilities that arise from this conclusion and a core assumption of the paper, i.e., that some dominant faith-based health institutions can legitimately request, and expect, that provincial/territorial governments pay them a measure of respect in their operational, health-care-delivery decision making because of these institutions’ long history of providing high quality, health care in Canada. It is further suggested that provincial/territorial governments only allow large, publicly funded, faith-based health care organizations to enact a conditional version of accommodation on the basis of institutional conscientious objection to MAiD in circumstances where the organization has entered into a formal agreement with the relevant health department to meet the proposed, compromise conditions (or a relevantly-similar set of conditions).

Long-term effects of copper exposure to agricultural soil function and microbial community structure at a controlled and experimental field site

The long-term effect of heavy metals on soil microbial communities and their function is relatively unknown and little work has been done in field settings. To address this gap, we revisited a field-based experiment, 12 years after the application of copper (Cu) to agricultural soils, with treatment concentrations ranging from 0 to 3310 mg Cu kg^-1 soil. We measured the long-term effects of Cu exposure to soils using multiple functionality assessments and environmental DNA-based community analyses. The assessment results revealed that soils that received moderate to high Cu doses had still not recovered functionality 12-years post exposure. However, plots that received doses of 200 mg kg^-1 Cu or less appeared to have a functionality index not dissimilar to control plots. Environmental DNA analyses of the microbial communities revealed a high level of beta diversity in low Cu treatment plots, whereas communities within high Cu treatment plots had similar community structures to one another (low beta diversity), indicating that specific Cu-tolerant or dormant taxa are selected for in high-Cu environments. Interestingly, high Cu plots had higher within-sample taxa counts (alpha diversity) compared with controls and low Cu plots. We hypothesise that taxa in high Cu plots activated dormancy mechanisms, such that their genetic signal remained present, whilst the functionality of the soil was reduced. Many species identified in high Cu plots are known to have associated dormancy mechanisms and survive in high stress environments. Understanding how these mechanisms collectively contribute to contaminant outcomes is of great importance for the goals of predicting and managing microbial communities and their function. As we found that Cu concentrations above 200 mg kg^-1 can cause significant functionality loss and a selective pressure on microbial communities, it is recommended that Cu concentrations above 200 mg kg^-1are avoided in agricultural soils.

The involvement of regulatory T cells in amyotrophic lateral sclerosis and their therapeutic potential

Neuroinflammation, meaning the establishment of a diffuse inflammatory condition in the CNS, is one of the main hallmarks of amyotrophic lateral sclerosis (ALS). Recently, a crucial role of regulatory T cells (Tregs) in this disease has been outlined. Tregs are a T cell subpopulation with immunomodulatory properties. In this review, we discuss the physiology of Tregs and their role in ALS disease onset and progression. Evidence has demonstrated that in ALS patients Tregs are dramatically and progressively reduced in number and are less effective in promoting immune suppression. In addition, Tregs levels correlate with the rate of disease progression and patient survival. For this reason, Tregs are now considered a promising therapeutic target for neuroprotection in ALS. In this review, the clinical impact of these cells will be discussed and an overview of the current clinical trials targeting Tregs is also provided.

TDP43 proteinopathy is associated with aberrant DNA methylation in human amyotrophic lateral sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by motor neurone (MN) degeneration and death. ALS can be sporadic (sALS) or familial, with a number of associated gene mutations, including C9orf72 (C9ALS). DNA methylation is an epigenetic mechanism whereby a methyl group is attached to a cytosine (5mC), resulting in gene expression repression. 5mC can be further oxidized to 5-hydroxymethylcytosine (5hmC). DNA methylation has been studied in other neurodegenerative diseases, but little work has been conducted in ALS.

AIMS

To assess differences in DNA methylation in individuals with ALS and the relationship between DNA methylation and TDP43 pathology.

METHODS

Post mortem tissue from controls, sALS cases and C9ALS cases were assessed by immunohistochemistry for 5mC and 5hmC in spinal cord, motor cortex and prefrontal cortex. LMNs were extracted from a subset of cases using laser capture microdissection. DNA from these underwent analysis using the MethylationEPIC array to determine which molecular processes were most affected.

RESULTS

There were higher levels of 5mC and 5hmC in sALS and C9ALS in the residual lower motor neurones (LMNs) of the spinal cord. Importantly, in LMNs with TDP43 pathology there was less nuclear 5mC and 5hmC compared to the majority of residual LMNs that lacked TDP43 pathology. Enrichment analysis of the array data suggested RNA metabolism was particularly affected.

CONCLUSIONS

DNA methylation is a contributory factor in ALS LMN pathology. This is not so for glia or neocortical neurones.

Neuropathological characterization of a novel TANK binding kinase (TBK1) gene loss of function mutation associated with amyotrophic lateral sclerosis

AIMS

Mutations in TANK binding kinase gene (TBK1) are causative in amyotrophic lateral sclerosis (ALS), however correlations between clinical features and TBK1 mutations have not been fully elucidated. We aimed to identify and compare TBK1 mutations to clinical features in a cohort of ALS patients from Northern England.

METHODS

TBK1 mutations were analysed in 290 ALS cases. Immunohistochemistry was performed in brain and spinal cord of one case with a novel in-frame deletion.

RESULTS

Seven TBK1 variants were identified, including one novel in-frame deletion (p.85delIle). In silico analysis and literature suggested four variants were pathogenic, and three were variants of uncertain significance or benign. Post-mortem immunohistochemistry established an individual with the novel in-frame deletion had classical ALS and Type B FTLD-TDP pathology, with no changes in TBK1 staining or interferon regulatory factor IRF3.

CONCLUSIONS

TBK1 mutations were present in 1.38% of our cohort, and screening showed no clear genotype-phenotype associations compared to other genetic and sporadic ALS cases. TBK1 immunohistochemistry was consistent with previously published literature and we are the first to show no differential expression of interferon regulatory factor IRF3, a downstream effector of TBK1 in the immune pathway, in the TBK1-mutant tissue, compared to controls.

Balancing competing interests and obligations in mental health-care practice and policy

It is often challenging for mental health-care providers and health organizations to perform their various roles and to meet their varied obligations. In complex mental health-care circumstances the concurrent application of relevant ethical principles and values often leads to the emergence of completing obligations that need to be carefully weighed and balanced in the making of care-related decisions. Although some clinical circumstances, such as those potentially triggering the duty to warn, are adequately guided by existing rules based on legal precedents, there is a gap in decision-making support in other mental health-care domains. This article proposes that a set of targeted, decision-making approaches be developed to assist in the handling of specific, challenging circumstances. By way of illustration, two novel approaches are introduced; that is, choosing to work within a moral relational space of optimal therapeutic engagement (at the micro level of clinical practice), and the use of a health policy development approach that instantiates deliberative engagement (at the meso and macro levels of health organization).

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

The PEN & PAD Medical Record Model: Development of a Nursing Record for Hospital-based Care of the Elderly

The PEN & PAD Medical Record model describes a framework for an information model, designed to meet the requirements of an electronic medical record. This model has been successfully tested in a computer-based record system for General Practitioners as part of the PEN & PAD (GP) Project.

Experiences of using the model for developing computer-based nursing records are reported. Results show that there are some problems with directly applying the model to the nursing domain. Whilst the main purpose of the nursing record is to document and communicate a patient’s care, it has several other, possibly incompatible, roles. Furthermore, the structure and content of the information contained within the nursing record is heavily influenced by the need for the nursing profession to visibly demonstrate the philosophical frameworks underlying their work. By providing new insights into the professional background of nursing records, this work has highlighted the need for nurses to clarify and make explicit their uses of information, and also provided them with some tools to assist in this task.

Morally-Relevant Similarities and Differences Between Assisted Dying Practices in Paradigm and Non-Paradigm Circumstances: Could They Inform Regulatory Decisions?

There has been contentious debate over the years about whether there are morally relevant similarities and differences between the three practices of continuous deep sedation until death, physician-assisted suicide, and voluntary euthanasia. Surprisingly little academic attention has been paid to a comparison of the uses of these practices in the two types of circumstances in which they are typically performed. A comparative domains of ethics analysis methodological approach is used in the paper to compare 1) the use of the three practices in paradigm circumstances, and 2) the use of the practices in paradigm circumstances to their use in non-paradigm circumstances. The analytical outcomes suggest that a bright moral line cannot be demonstrated between any two of the practices in paradigm circumstances, and that there are significant, morally-relevant distinctions between their use in paradigm and non-paradigm circumstances. A thought experiment is employed to illustrate how these outcomes could possibly inform the decisions of hypothetical deliberators who are engaged in the collaborative development of assisted dying regulatory frameworks.

The forgotten coracoid: A case report of a coracoid fracture in a male cyclist

A fall onto the shoulder is a common mechanism of injury in cyclists. However, coracoid fractures remain unreported in the literature in this population. These authors report a case of a coracoid fracture missed on the initial plain film radiographs. Whilst these fractures can be easily missed on standard trauma series radiographs of the shoulder, alternate views and other imaging modalities can be used to detect these fractures. Clinical suspicion, judicious imaging and accurate diagnosis of these fractures are important, as stability of the coracoid influences the entire superior shoulder suspensory complex which allows normal function of the shoulder joint.

Is There a Particular Ethical Practice and Policy Space in North America for Uncontrolled Kidney Donation after Circulatory Death?

Despite successful transplantation outcomes in Europe, uncontrolled organ donation after circulatory determination of death (uDCDD) has essentially been a non-starter in North America. In this paper, I identify and explore a set of interesting, ethics-related considerations that are of relevance to this organ donation-transplantation practice. The analysis provides a theoretical platform for my development of a proposal for the creation of a particular ethical practice and policy space for kidney uDCDD in the U.S. and Canada that recognizes and aims to effectively address the various, identified challenges and constraints.

Organ donation after assisted death: Is it more or less ethically-problematic than donation after circulatory death?

A provocative question has emerged since the Supreme Court of Canada's decision on assisted dying: Should Canadians who request, and are granted, an assisted death be considered a legitimate source of transplantable organs? A related question is addressed in this paper: is controlled organ donation after assisted death (cDAD) more or less ethically-problematic than standard, controlled organ donation after circulatory determination of death (cDCDD)? Controversial, ethics-related dimensions of cDCD that are of relevance to this research question are explored, and morally-relevant distinctions between cDAD and cDCD are identified. In addition, a set of morally-relevant advantages of one practice over the other is uncovered, and a few potential, theoretical issues specifically related to cDAD practice are articulated. Despite these concerns, the analysis suggests a counterintuitive conclusion: cDAD is, overall, less ethically-problematic than cDCDD. The former practice better respects the autonomy interests of the potential donor, and a claim regarding irreversibility of cessation of the donor's circulatory function in the cDAD context can be supported. Further, with cDAD, there is no possibility that the donor will have negative sensory experiences during organ procurement surgery. Although the development of appropriate policy-decision and regulatory approaches in this domain will be complex and challenging, the comparative ethical analysis of these two organ donation practices has the potential to constructively inform the deliberations of relevant stakeholders, resource persons and decision makers.

Development and Testing of a Cognitive Behavioral Therapy Resource for Children's Dental Anxiety

Cognitive Behavioral Therapy (CBT) is an evidence-based treatment for dental anxiety; however, access to therapy is limited. The current study aimed to develop a self-help CBT resource for reducing dental anxiety in children, and to assess the feasibility of conducting a trial to evaluate the treatment efficacy and cost-effectiveness of such an intervention. A mixed methods design was employed. Within phase 1, a qualitative "person-based" approach informed the development of the self-help CBT resource. This also employed guidelines for the development and evaluation of complex interventions. Within phase 2, children, aged between 9 and 16 y, who had elevated self-reported dental anxiety and were attending a community dental service or dental hospital, were invited to use the CBT resource. Children completed questionnaires, which assessed their dental anxiety and health-related quality of life (HRQoL) prior to and following their use of the resource. Recruitment and completion rates were recorded. Acceptability of the CBT resource was explored using interviews and focus groups with children, parents/carers and dental professionals. For this analysis, the authors adhered to the Mixed Methods Appraisal Tool criteria. There were 24 families and 25 dental professionals participating in the development and qualitative evaluation of the CBT resource for children with dental anxiety. A total of 56 children agreed to trial the CBT resource (66% response rate) and 48 of these children completed the study (86% completion rate). There was a significant reduction in dental anxiety (mean score difference = 7.7, t = 7.9, df = 45, P < 0.001, Cohen's d ES = 1.2) and an increase in HRQoL following the use of the CBT resource (mean score difference = -0.03, t = 2.14, df = 46, P < 0.05, Cohen's d ES = 0.3). The self-help approach had high levels of acceptability to stakeholders. These findings provide preliminary evidence for the effectiveness and acceptability of the resource in reducing dental anxiety in children and support the further evaluation of this approach in a randomized control trial. Knowledge Transfer Statement: This study details the development of a guided self-help Cognitive Behavioral Therapy resource for the management of dental anxiety in children and provides preliminary evidence for the feasibility and acceptability of this approach with children aged between 9 and 16 y. The results of this study will inform the design of a definitive trial to examine the treatment- and cost-effectiveness of the resource for reducing dental anxiety in children.

Genetic variation among 82 pharmacogenes: The PGRNseq data from the eMERGE network

Genetic variation can affect drug response in multiple ways, although it remains unclear how rare genetic variants affect drug response. The electronic Medical Records and Genomics (eMERGE) Network, collaborating with the Pharmacogenomics Research Network, began eMERGE‐PGx, a targeted sequencing study to assess genetic variation in 82 pharmacogenes critical for implementation of “precision medicine.” The February 2015 eMERGE‐PGx data release includes sequence‐derived data from ∼5,000 clinical subjects. We present the variant frequency spectrum categorized by variant type, ancestry, and predicted function. We found 95.12% of genes have variants with a scaled Combined Annotation‐Dependent Depletion score above 20, and 96.19% of all samples had one or more Clinical Pharmacogenetics Implementation Consortium Level A actionable variants. These data highlight the distribution and scope of genetic variation in relevant pharmacogenes, identifying challenges associated with implementing clinical sequencing for drug treatment at a broader level, underscoring the importance for multifaceted research in the execution of precision medicine.

Managing Profound Suffering at the End-of-Life: Should expanding access to continuous deep sedation be the priority?

This paper argues that in addressing and managing profound suffering at the end-of-life, the priority should not be the legalization of physician-assisted suicide or voluntary active euthanasia in jurisdictions where these practices are not currently available. Rather, concerted efforts should be made by society and the healthcare provider community to expand patient access to proportionate distress-relieving sedation and continuous deep sedation.

Balancing Legitimate Critical-Care Interests: Setting Defensible Care Limits Through Policy Development

Critical-care decision making is highly complex, given the need for health care providers and organizations to consider, and constructively respond to, the diverse interests and perspectives of a variety of legitimate stakeholders. Insights derived from an identified set of ethics-related considerations have the potential to meaningfully inform inclusive and deliberative policy development that aims to optimally balance the competing obligations that arise in this challenging, clinical decision-making domain. A potential, constructive outcome of such policy engagement is the collaborative development of an as-fair-as-possible dispute resolution process that incorporates an appropriated-justified, defensible critical-care obligation threshold.

Invited review: decoding the pathophysiological mechanisms that underlie RNA dysregulation in neurodegenerative disorders: a review of the current state of the art

Altered RNA metabolism is a key pathophysiological component causing several neurodegenerative diseases. Genetic mutations causing neurodegeneration occur in coding and noncoding regions of seemingly unrelated genes whose products do not always contribute to the gene expression process. Several pathogenic mechanisms may coexist within a single neuronal cell, including RNA/protein toxic gain-of-function and/or protein loss-of-function. Genetic mutations that cause neurodegenerative disorders disrupt healthy gene expression at diverse levels, from chromatin remodelling, transcription, splicing, through to axonal transport and repeat-associated non-ATG (RAN) translation. We address neurodegeneration in repeat expansion disorders [Huntington's disease, spinocerebellar ataxias, C9ORF72-related amyotrophic lateral sclerosis (ALS)] and in diseases caused by deletions or point mutations (spinal muscular atrophy, most subtypes of familial ALS). Some neurodegenerative disorders exhibit broad dysregulation of gene expression with the synthesis of hundreds to thousands of abnormal messenger RNA (mRNA) molecules. However, the number and identity of aberrant mRNAs that are translated into proteins - and how these lead to neurodegeneration - remain unknown. The field of RNA biology research faces the challenge of identifying pathophysiological events of dysregulated gene expression. In conclusion, we discuss current research limitations and future directions to improve our characterization of pathological mechanisms that trigger disease onset and progression.

Imaging nanoparticle-algae interactions in three dimensions using Cytoviva microscopy

Plasmonic resonances of metal-based nanoparticles are increasingly used for ultrasensitive imaging assays. In this context, the Cytoviva(TM) microscopy platform has greatly gained in popularity. In essence, Cytoviva is an optimized dark field microscope that permits detection of particles down to a few nanometers in size. A significant limitation of Cytoviva up to now has been that it only provided for single plane imaging. The datasets produced by this technique therefore only show a partial view of the sample - not ideally suited to analysis. Here we explain how to overcome this limitation by mounting the Cytoviva condenser on an automated microscope with Z-scanning capability. Our method allows three-dimensional mapping of nanoparticles in their full three-dimensional cellular context. We apply this technique to study the interaction of silver and cerium dioxide nanoparticles with cells of the green alga, Pseudokirchneriella subcapitata, a system of significant environmental relevance because algae underlie much of the aquatic food chain. Our objective was to develop a technique to visualize in detail the interaction of nanoparticles with cells in three dimensions, such that one may, for example, determine whether a particular nanoparticle is inside a cell, at its very surface, or at a distance from it.

The immunobiology of cobalt: demonstration of a potential aetiology for inflammatory pseudotumours after metal-on-metal replacement of the hip

Abnormal wear of cobalt-containing metal-on-metal joints is associated with inflammatory pseudotumours. Cobalt ions activate human toll-like receptor 4 (TLR4), which normally responds to bacterial lipopolysaccharide (LPS) in sepsis. Activation of TLR4 by LPS increases the expression of chemokines IL-8 and CXCL10, which recruit leukocytes and activated T-cells, respectively. This study was designed to determine whether cobalt induces a similar inflammatory response to LPS by promoting the expression of IL-8 and CXCL10. A human monocytic cell line, derived from acute monocytic leukaemia, was treated with cobalt ions and expression of IL-8 and CXCL10 measured at mRNA and protein levels. Cobalt-treated macrophages showed a 60-fold increase in IL-8 mRNA, and an eightfold increase in production of the mature chemokine (both p < 0.001); expression of the CXCL10 gene and protein was also significantly increased by cobalt (both p < 0.001). Experiments were also performed in the presence of CLI-095, a TLR4-specific antagonist which abrogated the cobalt-mediated increase in IL-8 and CXCL10 expression. These findings suggest that cobalt ions induce inflammation similar to that observed during sepsis by the simultaneous activation of two TLR4-mediated signalling pathways. These pathways result in increased production of IL-8 and CXCL10, and may be implicated in pseudotumour formation following metal-on-metal replacement.