How are Trypanosoma brucei receptors protected from host antibody-mediated attack?

Trypanosoma brucei is the causal agent of African Trypanosomiasis in humans and other animals. It maintains a long-term infection through an antigenic variation based population survival strategy. To proliferate in a mammal, T. brucei acquires iron and haem through the receptor mediated uptake of host transferrin and haptoglobin-hemoglobin respectively. The receptors are exposed to host antibodies but this does not lead to clearance of the infection. Here we discuss how the trypanosome avoids this fate in the context of recent findings on the structure and cell biology of the receptors.

Relationship Between Clinician Language and the Success of Behavioral Weight Loss Interventions : A Mixed-Methods Cohort Study.

BACKGROUND: International guidelines recommend that primary care clinicians recognize obesity and offer treatment opportunistically, but there is little evidence on how clinicians can discuss weight and offer treatment in ways that are well received and effective. OBJECTIVE: To examine relationships between language used in the clinical visit and patient weight loss. DESIGN: Mixed-methods cohort study. SETTING: 38 primary care clinics in England participating in the Brief Intervention for Weight Loss trial. PARTICIPANTS: 246 patients with obesity seen by 87 general practitioners randomly sampled from the intervention group of the randomized clinical trial. MEASUREMENTS: Conversation analysis of recorded discussions between 246 patients with obesity and 87 clinicians regarding referral to a 12-week behavioral weight management program offered as part of the randomized clinical trial. Clinicians' interactional approaches were identified and their association with patient weight loss at 12 months (primary outcome) was examined. Secondary outcomes included patients' agreement to attend weight management, attendance, loss of 5% body weight, actions taken to lose weight, and postvisit satisfaction. RESULTS: Three interactional approaches were identified on the basis of clinicians' linguistic and paralinguistic practices: creating a sense of referrals as "good news" related to the opportunity of the referral (n = 62); "bad news," focusing on the harms of obesity (n = 82); or neutral (n = 102). Outcome data were missing from 57 participants, so weighted analyses were done to adjust for missingness. Relative to neutral news, good news was associated with increased agreement to attend the program (adjusted risk difference, 0.25 [95% CI, 0.15 to 0.35]), increased attendance (adjusted risk difference, 0.45 [CI, 0.34 to 0.56]), and weight change (adjusted difference, -3.60 [CI, -6.58 to -0.62]). There was no evidence of differences in mean weight change comparing bad and neutral news, and no evidence of differences in patient satisfaction across all 3 approaches. LIMITATIONS: Data were audio only, so body language and nonverbal cues could not be assessed. There is potential for selection bias and residual confounding. CONCLUSION: When raising the topic of excess weight in clinical visits, presenting weight loss treatment as a positive opportunity is associated with greater uptake of treatment and greater weight loss. PRIMARY FUNDING SOURCE: National Institute for Health and Care Research School for Primary Care Research and the Foundation for the Sociology of Health and Illness.

The Basis of Patient Resistance to Opportunistic Discussions About Weight in Primary Care.

Clinicians expect that talking to patients with obesity about potential/future weight loss will be a difficult conversation, especially if it is not the reason that a patient is seeking medical help. Despite this expectation, many governments ask clinicians to take every opportunity to talk to patients about weight to help manage increasing levels of obesity. Although this is recommended, little is known about what happens in consultations when clinicians opportunistically talk to patients about weight, and if the anticipated difficulties are reality. This paper examines displays of explicit patient resistance following opportunistic weight-loss conversations initiated by GPs. We analyzed audio recordings and transcribed them for conversation analysis. We focused on the precursors of explicit resistance displays during opportunistic weight loss discussions, the format of the resistance, and the ways it was managed by GPs. We found relatively few instances of explicit resistance displays. When it did occur, rather than be related to the opportunistic nature of the advice, or the topic of weight itself, resistance was nuanced and associated to the sensitivity of the GPs managing unknown patient levels of awareness of weight loss benefits, or prior efforts to lose weight. Clinicians tended not to challenge this resistance from patients, and we suggest this tactic may be acceptable to patients and help foster the long-term collaborative relationships needed to tackle obesity. Data are in British English.

Discussing weight loss opportunistically and effectively in family practice: a qualitative study of clinical interactions using conversation analysis in UK family practice.

BACKGROUND: GPs are encouraged to make brief interventions to support weight loss, but they report concern about these conversations, stating that they need more details on what to say. Knowing how engage in these conversations could encourage GPs to deliver brief interventions for weight loss more frequently. OBJECTIVE: To examine which specific words and phrases were successful in achieving conversational alignment and minimizing misunderstanding, contributing to effective interventions. METHODS: A conversation analysis of English family practice patients participating in a trial of opportunistic weight-management interventions, which incorporated the offer of referral to community weight-management services (CWMS). Qualitative conversation analysis was applied to 246 consultation recordings to identify communication patterns, which contributed to clear, efficient interventions. RESULTS: Analysis showed variation in how GPs delivered interventions. Some ways of talking created misunderstandings or misalignment, while others avoided these. There were five components of clear and efficient opportunistic weight-management referrals. These were (i) exemplifying CWMS with a recognizable brand name (ii) saying weight-management 'programme' or 'service', rather than 'group' or 'club' (iii) stating that the referral is 'free' early on (iv) saying the number CWMS visits available on referral (v) stating that the CWMS programme available was 'local'. CONCLUSIONS: When making a brief opportunistic intervention to support weight loss, clinicians can follow these five steps to create a smooth and efficient intervention. Knowing this may allay clinicians' fears about these consultations being awkward and improve adherence to guidelines.

Determinants of GPI-PLC localisation to the flagellum and access to GPI-anchored substrates in trypanosomes.

In Trypanosoma brucei, glycosylphosphatidylinositol phospholipase C (GPI-PLC) is a virulence factor that releases variant surface glycoprotein (VSG) from dying cells. In live cells, GPI-PLC is localised to the plasma membrane where it is concentrated on the flagellar membrane, so activity or access must be tightly regulated as very little VSG is shed. Little is known about regulation except that acylation within a short internal motif containing three cysteines is necessary for GPI-PLC to access VSG in dying cells. Here, GPI-PLC mutants have been analysed both for subcellular localisation and for the ability to release VSG from dying cells. Two sequence determinants necessary for concentration on the flagellar membrane were identified. First, all three cysteines are required for full concentration on the flagellar membrane. Mutants with two cysteines localise predominantly to the plasma membrane but lose some of their flagellar concentration, while mutants with one cysteine are mainly localised to membranes between the nucleus and flagellar pocket. Second, a proline residue close to the C-terminus, and distant from the acylated cysteines, is necessary for concentration on the flagellar membrane. The localisation of GPI-PLC to the plasma but not flagellar membrane is necessary for access to the VSG in dying cells. Cellular structures necessary for concentration on the flagellar membrane were identified by depletion of components. Disruption of the flagellar pocket collar caused loss of concentration whereas detachment of the flagellum from the cell body after disruption of the flagellar attachment zone did not. Thus, targeting to the flagellar membrane requires: a titratable level of acylation, a motif including a proline, and a functional flagellar pocket. These results provide an insight into how the segregation of flagellar membrane proteins from those present in the flagellar pocket and cell body membranes is achieved.

Clinical Decision Support Systems Used in Transplantation: Are They Tools for Success or an Unnecessary Gadget? A Systematic Review.

Although clinical decision support systems (CDSSs) have been used since the 1970s for a wide variety of clinical tasks including optimization of medication orders, improved documentation, and improved patient adherence, to date, no systematic reviews have been carried out to assess their utilization and efficacy in transplant medicine. The aim of this study is to systematically review studies that utilized a CDSS and assess impact on patient outcomes. A total of 48 articles were identified as meeting the author-derived inclusion criteria, including tools for posttransplant monitoring, pretransplant risk assessment, waiting list management, immunosuppressant management, and interpretation of histopathology. Studies included 15 984 transplant recipients. Tools aimed at helping with transplant patient immunosuppressant management were the most common (19 studies). Thirty-four studies (85%) found an overall clinical benefit following the implementation of a CDSS in clinical practice. Although there are limitations to the existing literature, current evidence suggests that implementing CDSS in transplant clinical settings may improve outcomes for patients. Limited evidence was found using more advanced technologies such as artificial intelligence in transplantation, and future studies should investigate the role of these emerging technologies.

What happens when patients say "no" to offers of referral for weight loss? - Results and recommendations from a conversation analysis of primary care interactions.

OBJECTIVE: Guidelines recommend that clinicians should offer patients with obesity referrals to weight management services. However, clinicians and patients worry that such conversations will generate friction, and the risk of this is greatest when patients say no. We examined how doctors actually respond to patient refusals, and how patients reacted to clinicians in turn. METHODS: Conversation analysis of 226 GP-patient interactions recorded during a clinical trial of weight management referrals in UK primary care. RESULTS: Some clinicians responded to refusals by delivering further information or offering referral again. These actions treated patient refusals as unwelcome, and acted to pursue acceptance instead. However, pursuit did not lead to acceptance. Rather, pursuing acceptance lengthened consultations and led to frustration, offence, or anger. Clinicians who accepted refusals and closed the consultation avoided friction and negative emotional displays. CONCLUSION: Patient refusals have the potential to create negative consequences in the consultation and clinician responses were key in avoiding these. When clinicians acknowledged the legitimacy of patient refusals, negative consequences were avoided, and the conversation was briefer and smoother. PRACTICE IMPLICATIONS: When patients refuse the offer of a free weight management referral, GPs should accept this refusal, rather than trying to persuade patients to accept.

Talking delicately: Providing opportunistic weight loss advice to people living with obesity.

Obesity is a major worldwide public health problem. Clinicians are asked to communicate public health messages, including encouraging and supporting weight loss, during consultations with patients living with obesity. However, research shows that talking about weight with patients rarely happens and both parties find it difficult to initiate. Current guidelines on how to have such conversations do not include evidence-based examples of what to say, when to say it and how to avoid causing offence (a key concern for clinicians). To address this gap, we examined 237 audio recorded consultations between clinicians and patients living with obesity in the UK in which weight was discussed opportunistically. Conversation analysis revealed that framing advice as depersonalised generic information was one strategy clinicians used when initiating discussions. This contrasted to clinicians who made advice clearly relevant and personalised to the patient by first appraising their weight. However not all personalised forms of advice worked equally well. Clinicians who spoke delicately when personalising the discussion avoided the types of patient resistance that we found when clinicians were less delicate. More delicate approaches included forecasting upcoming discussion of weight along with delicacy markers in talk (e.g. strategic use of hesitation). Our findings suggest that clinicians should not avoid talking about a patient's weight, but should speak delicately to help maintain good relationships with patients. The findings also demonstrate the need to examine communication practices to develop better and specific guidance for clinicians. Data are in British English.

Invariant surface glycoprotein 65 of Trypanosoma brucei is a complement C3 receptor.

African trypanosomes are extracellular pathogens of mammals and are exposed to the adaptive and innate immune systems. Trypanosomes evade the adaptive immune response through antigenic variation, but little is known about how they interact with components of the innate immune response, including complement. Here we demonstrate that an invariant surface glycoprotein, ISG65, is a receptor for complement component 3 (C3). We show how ISG65 binds to the thioester domain of C3b. We also show that C3 contributes to control of trypanosomes during early infection in a mouse model and provide evidence that ISG65 is involved in reducing trypanosome susceptibility to C3-mediated clearance. Deposition of C3b on pathogen surfaces, such as trypanosomes, is a central point in activation of the complement system. In ISG65, trypanosomes have evolved a C3 receptor which diminishes the downstream effects of C3 deposition on the control of infection.

The glycosylphosphatidylinositol-PLC in Trypanosoma brucei forms a linear array on the exterior of the flagellar membrane before and after activation.

Bloodstream forms of Trypanosoma brucei contain a glycosylphosphatidylinositol-specific phospholipase C (GPI-PLC) that cleaves the GPI-anchor of the variable surface glycoprotein (VSG). Its location in trypanosomes has been controversial. Here, using confocal microscopy and surface labelling techniques, we show that the GPI-PLC is located exclusively in a linear array on the outside of the flagellar membrane, close to the flagellar attachment zone, but does not co-localize with the flagellar attachment zone protein, FAZ1. Consequently, the GPI-PLC and the VSG occupy the same plasma membrane leaflet, which resolves the topological problem associated with the cleavage reaction if the VSG and the GPI-PLC were on opposite sides of the membrane. The exterior location requires the enzyme to be tightly regulated to prevent VSG release under basal conditions. During stimulated VSG release in intact cells, the GPI-PLC did not change location, suggesting that the release mechanism involves lateral diffusion of the VSG in the plane of the membrane to the fixed position of the GPI-PLC.

Role-Play as Responsible Robotics: The Virtual Witness Testimony Role-Play Interview for Investigating Hazardous Human-Robot Interactions.

The development of responsible robotics requires paying attention to responsibility within the research process in addition to responsibility as the outcome of research. This paper describes the preparation and application of a novel method to explore hazardous human-robot interactions. The Virtual Witness Testimony role-play interview is an approach that enables participants to engage with scenarios in which a human being comes to physical harm whilst a robot is present and may have had a malfunction. Participants decide what actions they would take in the scenario and are encouraged to provide their observations and speculations on what happened. Data collection takes place online, a format that provides convenience as well as a safe space for participants to role play a hazardous encounter with minimal risk of suffering discomfort or distress. We provide a detailed account of how our initial set of Virtual Witness Testimony role-play interviews were conducted and describe the ways in which it proved to be an efficient approach that generated useful findings, and upheld our project commitments to Responsible Research and Innovation. We argue that the Virtual Witness Testimony role-play interview is a flexible and fruitful method that can be adapted to benefit research in human robot interaction and advance responsibility in robotics.

Barely sufficient practices in scientific computing.

The importance of software to modern research is well understood, as is the way in which software developed for research can support or undermine important research principles of findability, accessibility, interoperability, and reusability (FAIR). We propose a minimal subset of common software engineering principles that enable FAIRness of computational research and can be used as a baseline for software engineering in any research discipline.

'I've put weight on cos I've bin inactive, cos I've 'ad me knee done': moral work in the obesity clinic.

As governments and healthcare systems grow increasingly concerned with the current obesity 'epidemic', sociological interest in the condition has also increased. Despite the emergence of work discussing obesity as a social phenomenon, the sociological dimensions of medical weight-loss treatments for obesity remain underexplored. This paper reports on a conversation analytic (CA) study and describes how moral issues surrounding weight and patienthood become visible when doctors and patients discuss obesity. Consultations in two UK National Health Service clinics were video-recorded and analysed to identify recurring patterns of interaction. This paper describes how patients answer opening questions: questions which begin the consultation, enabling patients to report their medical status. Analysis reveals that when producing their answers, patients typically imply either 'success' or 'lack of success' in their weight-loss progress. Whilst doing so, they construct their personal agency in different ways, crediting themselves for implied successes and resisting responsibility for lack of success. Through interaction the doctor and patient collaboratively construct obesity as a moral issue. The moral obligations invoked share similarities with certain perceived normative dynamics surrounding obesity and the responsibilities of patienthood. These findings have relevance to healthcare practice and add to sociological understanding of the modern obesity 'crisis'.

GP-delivered brief weight loss interventions: a cohort study of patient responses and subsequent actions, using conversation analysis in UK primary care.

BACKGROUND: Guidelines encourage GPs to make brief opportunistic interventions to support weight loss. However, GPs fear that starting these discussions will lead to lengthy consultations. Recognising that patients are committed to take action could allow GPs to shorten brief interventions. AIM: To examine which patient responses indicated commitment to action, and the time saved if these had been recognised and the consultation closed sooner. DESIGN AND SETTING: A mixed-method cohort study of UK primary care patients participating in a trial of opportunistic weight management interventions. METHOD: Conversation analysis was applied to 226 consultation audiorecordings to identify types of responses from patients that indicated that an offer of referral to weight management was well received. Odds ratios (OR) were calculated to examine associations between response types and likelihood of weight management programme attendance. RESULTS: Affirmative responses, for example 'yes', displayed no conversational evidence that the referral was well received and showed no association with attendance: 'yes' (OR 1.2, 95% confidence interval [CI] = 0.37 to 3.95, P = 0.97). However, 'oh'-prefaced responses and marked positive responses, for example 'lovely', showed conversational evidence of enthusiasm and were associated with higher odds of commercial weight management service attendance. Recognising these could have saved doctors a mean of 31 seconds per consultation. CONCLUSION: When doctors make brief opportunistic interventions that incorporate the offer of help, 'oh'-prefaced or marked positive responses indicate enthusiastic acceptance of the offer and a higher likelihood of take-up. Recognising these responses and moving swiftly to facilitate patient action would shorten the brief intervention in many cases.

Developmentally regulated instability of the GPI-PLC mRNA is dependent on a short-lived protein factor.

The expression of the vast majority of protein coding genes in trypanosomes is regulated exclusively at the post-transcriptional level. Developmentally regulated mRNAs that vary in levels of expression have provided an insight into one mechanism of regulation; a decrease in abundance is due to a shortened mRNA half-life. The decrease in half-life involves cis-acting elements in the 3' untranslated region of the mRNA. The trans-acting factors necessary for the increased rate of degradation remain uncharacterized. The GPI-PLC gene in Trypanosoma brucei encodes a phospholipase C expressed in mammalian bloodstream form, but not in the insect procyclic form. Here, it is reported that the differential expression of the GPI-PLC mRNA also results from a 10-fold difference in half-life. Second, the instability of the GPI-PLC mRNA in procyclic forms can be reversed by the inhibition of protein synthesis. Third, specifically blocking the translation of the GPI-PLC mRNA in procyclic forms by the inclusion of a hairpin in the 5' untranslated region does not result in stabilization of the mRNA. Thus, the effect of protein synthesis inhibitors in stabilizing the GPI-PLC mRNA operates in trans through a short-lived factor dependent on protein synthesis.

Candidate protein selection for diagnostic markers of African trypanosomiasis.

The ability to accurately diagnose the presence of an infective micro-organism is not only important for individual human and animal health and wellbeing, but is also central to surveillance programmes. Effective and sustainable control of many diseases in the developing world depends on the availability of field applicable diagnostics that are cheap, reliable, simple in design and application, and which provide immediate results. This review examines how the genome sequences can be used in the selection of potential candidate proteins for developing new serodiagnostics for African trypanosomiasis.