Review of Positron Emission Tomography at Royal Prince Alfred Hospital, CHERE Project Report No 18

This report is a review of the clinical uses, impacts on clinical management, clinical outcome and resource use of Positron Emission Tomography (PET) at Royal Prince Alfred Hospital (RPAH).Positron emission tomography

Comparison of Fas(Apo-1/CD95)- and perforin-mediated cytotoxicity in primary T lymphocytes

Cytolytic T lymphocytes kill target cells by two independent cytolytic mechanisms. One pathway depends on the polarized secretion of granule-stored proteins including perform and granzymes, causing target cell death through membrane and DNA damage. The second cytolytic effector system relies on the interaction of the Fas ligand (FasL) on the effector cell with its receptor (Fas) on the target cell, leading to apoptotic cell death. Using mixed lymphocyte culture (MLC)-derived primary T lymphocytes of perforin-knockout and gld (with non-functional FasL) mice, the molecular basis of the two killing mechanisms was compared. The activity of both pathways was dependent on extracellular Ca2+. Incubation of MLC-stimulated primary T cells with protein synthesis inhibitors prior to TCR triggering impaired FasL cell surface expression and abolished cytolytic activity, although the cells exhibited an intracellular pool of FasL. The perforin-dependent mechanism induced cell death more rapidly, although both pathways ultimately showed similar killing efficiencies. Both pathways induced comparable levels of DNA degradation, but Fas-induced membrane damage was less pronounced. We conclude that upon TCR triggering FasL may be recruited in part from pre-existing intracellular stores. However, efficient induction of target cell death still depends on the continuous biosynthesis of FasL molecule

T-cell intracellular antigens in health and disease

T-cell intracellular antigen 1 (TIA1) and TIA1-related/like protein (TIAR/TIAL1) are 2 proteins discovered in 1991 as components of cytotoxic T lymphocyte granules. They act in the nucleus as regulators of transcription and pre-mRNA splicing. In the cytoplasm, TIA1 and TIAR regulate and/or modulate the location, stability and/or translation of mRNAs. As knowledge of the different genes regulated by these proteins and the cellular/biological programs in which they are involved increases, it is evident that these antigens are key players in human physiology and pathology. This review will discuss the latest developments in the field, with physiopathological relevance, that point to novel roles for these regulators in the molecular and cell biology of higher eukaryotes.Ministry Economic Affairs and Competitiveness through FEDER funds (BFU2008–00354, BFU2011–29653 and BFU2014–57735-R). The CBMSO receives an institutional grant from Fundación Ramón Areces.Peer Reviewe

Characterization of the non-functional Fas ligand of gld mice

Mice homozygous for either the gld or Ipr mutation develop autoimmune diseases and progressive lymphadenopathy. The Ipr mutation Is characterized by the absence of unctional Fas, whereas gld mice exhibit an inactive FasL due to a point mutation proximal to the extracellular C-terminus. The structural repercussions of this amino acid substitution remain unknown. Here we report that FasL Is expressed at similar levels on the surface of activated T lymphocytes from gld and wild-type mice. Using a polyclonal anti-FasL antibody, Indistinguishable amounts of a 40 kDa protein are detected In both gld and wild-type splenocytes. The molecular model of FasL, based on the known structure of TNF-α, predicts that the Phe→Leu gld mutation is located at the protomer interface which Is close to the FasR Interaction site. We conclude that the gld mutation allows normal FasL biosynthesis, surface expression and ollgomerlzatlon, but induces structural alterations to the Fas binding region leading to the phenotypic changes observe

The Good Behaviour Game intervention to improve behavioural and other outcomes for children aged 7–8 years: a cluster RCT

BackgroundUniversal, school-based behaviour management interventions can produce meaningful improvements in children’s behaviour and other outcomes. However, the UK evidence base for these remains limited.ObjectiveThe objective of this trial was to investigate the impact, value for money and longer-term outcomes of the Good Behaviour Game. Study hypotheses centred on immediate impact (hypothesis 1); subgroup effects (at-risk boys, hypothesis 2); implementation effects (dosage, hypothesis 3); maintenance/sleeper effects (12- and 24-month post-intervention follow-ups, hypothesis 4); the temporal association between mental health and academic attainment (hypothesis 5); and the health economic impact of the Good Behaviour Game (hypothesis 6).DesignThis was a two-group, parallel, cluster-randomised controlled trial. Primary schools (n = 77) were randomly assigned to implement the Good Behaviour Game for 2 years or continue their usual practice, after which there was a 2-year follow-up period.SettingThe trial was set in primary schools across 23 local authorities in England.ParticipantsParticipants were children (n = 3084) aged 7–8 years attending participating schools.InterventionThe Good Behaviour Game is a universal behaviour management intervention. Its core components are classroom rules, team membership, monitoring behaviour and positive reinforcement. It is played alongside a normal classroom activity for a set time, during which children work in teams to win the game to access the agreed rewards. The Good Behaviour Game is a manualised intervention delivered by teachers who receive initial training and ongoing coaching.Main outcome measuresThe measures were conduct problems (primary outcome; teacher-rated Strengths and Difficulties Questionnaire scores); emotional symptoms (teacher-rated Strengths and Difficulties Questionnaire scores); psychological well-being, peer and social support, bullying (i.e. social acceptance) and school environment (self-report Kidscreen survey results); and school absence and exclusion from school (measured using National Pupil Database records). Measures of academic attainment (reading, standardised tests), disruptive behaviour, concentration problems and prosocial behaviour (Teacher Observation of Child Adaptation Checklist scores) were also collected during the 2-year follow-up period.ResultsThere was no evidence that the Good Behaviour Game improved any outcomes (hypothesis 1). The only significant subgroup moderator effect identified was contrary to expectations: at-risk boys in Good Behaviour Game schools reported higher rates of bullying (hypothesis 2). The moderating effect of the amount of time spent playing the Good Behaviour Game was unclear; in the context of both moderate (≥ 1030 minutes over 2 years) and high (≥ 1348 minutes over 2 years) intervention compliance, there were significant reductions in children’s psychological well-being, but also significant reductions in their school absence (hypothesis 3). The only medium-term intervention effect was for peer and social support at 24 months, but this was in a negative direction (hypothesis 4). After disaggregating within- and between-individual effects, we found no temporal within-individual associations between children’s mental health and their academic attainment (hypothesis 5). Last, our cost–consequences analysis indicated that the Good Behaviour Game does not provide value for money (hypothesis 6).LimitationsLimitations included the post-test-only design for several secondary outcomes; suboptimal implementation dosage (mitigated by complier-average causal effect estimation); and moderate child-level attrition (18.5% for the primary outcome analysis), particularly in the post-trial follow-up period (mitigated by the use of full information maximum likelihood procedures).Future workQuestions remain regarding programme differentiation (e.g. how distinct is the Good Behaviour Game from existing behaviour management practices, and does this makes a difference in terms of its impact?) and if the Good Behaviour Game is impactful when combined with a complementary preventative intervention (as has been the case in several earlier trials).ConclusionThe Good Behaviour Game cannot be recommended based on the findings reported here

In vitro- and ex vivo-derived cytolytic leukocytes from granzyme A x B double knockout mice are defective in granule-mediated apoptosis but not lysis of target cells

Granzyme (gzm) A and gzmB have been implicated in Fas-independent nucleolytic and cytolytic processes exerted by cytotoxic T (Tc) cells, but the underlying mechanism(s) remains unclear. In this study, we compare the potential of Tc and natural killer (NK) cells of mice deficient in both gzmA and B (gzmAxB-/-) with those from single knockout mice deficient in gzmA (-/-), gzmB (-/-), or perforin (-/-) to induce nuclear damage and lysis in target cells. With the exception of perforin-/-, all in vitro- and ex vivo-derived Tc and NK cell populations from the mutant strains induced 51Cr-release in target cells at levels and with kinetics similar to those of normal mice. This contrasts with their capacity to induce apoptotic nuclear damage in target cells. In gzmAxB-/- mice, Tc/NK-mediated target cell DNA fragmentation was not observed, even after extended incubation periods (10 h), but was normal in gzmA-deficient and only impaired in gzmB-deficient mice in short-term (2-4 h), but not long-term (4-10 h), nucleolytic assays. This suggests that gzmA and B are critical for Tc/NK granule- mediated nucleolysis, with gzmB being the main contributor, while target cell lysis is due solely to perforin and independent of both proteases

Economic Retrieval-Augmented Generation for Large Language Model Services

Service providers increasingly use chatbots to extend their portfolio. However, out-of-the-box large language models (LLM) have limited domain knowledge that hinders their usage for particular use cases. Thus, service providers must utilize domain adoption to allow the implementation of more advanced chatbots. Recent LLM implementations apply retrieval-augmented generation (RAG) to give chatbot access to domain knowledge, e.g., in the form of a vector search additional to the LLM generation process. We compare three RAG implementations and their implications on performance and economic costs. We find that default RAG implementations might lack accuracy when considering specific characteristics in the vector search, e.g., a product category. Fine-tuning a lightweight transformer model for the structured extraction of information can increase the RAG performance while limiting costs. Besides, it has a low impact on the additional execution time compared to other RAG implementations

Privacy by Design: Data-Saving Activity Estimation Using Room-Based Non-Intrusive Load Monitoring for Ambient Assisted Living

Activity detection is crucial in enabling ambient assisted living (AAL). In this paper, we propose the usage of room-based energy disaggregation for activity detection in AAL environments. Non-intrusive load monitoring (NILM) utilizes the aggregate energy consumption data from households to predict components in the aggregate, enabling more privacy-preserving solutions. Most approaches use NILM while focusing on an appliance level, making them expensive in practice while raising privacy concerns by including more personal usage data. Utilizing a room-based NILM approach, we reduce the personal data while enabling a binary activity estimation across different rooms, which we evaluate on multiple sampling rates. In conclusion, the presented approach contributes to offering support for independent living for older adults or people with special needs. By doing so, it also aligns with the principles of data minimization and privacy protection, focusing on semi-private areas in the households, i.e., kitchen and living room environments

Integrins and their ligands in rheumatoid arthritis

Integrins play an important role in cell adhesion to the extracellular matrix and other cells. Upon ligand binding, signaling is initiated and several intracellular pathways are activated. This leads to a wide variety of effects, depending on cell type. Integrin activation has been linked to proliferation, secretion of matrix-degrading enzymes, cytokine production, migration, and invasion. Dysregulated integrin expression is often found in malignant disease. Tumors use integrins to evade apoptosis or metastasize, indicating that integrin signaling has to be tightly controlled. During the course of rheumatoid arthritis, the synovial tissue is infiltrated by immune cells that secrete large amounts of cytokines. This pro-inflammatory milieu leads to an upregulation of integrin receptors and their ligands in the synovial tissue. As a consequence, integrin signaling is enhanced, leading to enhanced production of matrix-degrading enzymes and cytokines. Furthermore, in analogy to invading tumors, synovial fibroblasts start invading and degrading cartilage, thereby generating extracellular matrix debris that can further activate integrins