46 research outputs found
What, where, and how : a proposal for structuring preliminary clinical evaluations
Used within the classroom and clinical practice setting the WHAT, WHERE, HOW method enhances student understanding of theoretical concepts of image interpretation and is readily open to assessment to demonstrate accuracy of diagnosis and content. The WHAT, WHERE, HOW structure allows students to break down appearances into components and make sense of even complex traumatic radiographic findings, instilling a feeling of competence and understanding. It is proposed that this structure be integrated into undergraduate and postgraduate education programs and courses, with the potential to develop knowledge and understanding of musculoskeletal anatomy, but also the confidence to provide a useful and meaningful role in clinical practice. It would also provide additional value to RadBench and enable the benchmarking of commentary.
Further adaption and development is being undertaken to develop the practice into other clinical areas such as non-trauma and chest radiography, and CT head interpretation.
The vision of the Society and College of Radiographer’s to introduce commenting skills as a competency for Radiography graduates by 20101 may have passed, but is very much alive and this work is a key step forward
The use of needle guidance software within interventional radiology
Cone Beam CT (CBCT) has allowed for the expansion of the examinations/procedures that can be performed within the interventional radiology suite. Many of these procedures were once only possible within CT, however with the availability of CBCT and needle guidance software within the interventional suite these exams can be brought into the Interventional setting. This has allowed for the improved safety and care of the patients whilst not limiting the
89
imaging facilities available to the radiologist. With improved experience, knowledge and confidence in using needle guidance even the most complex cases have the possibility of being performed within the interventional suite
Preliminary clinical evaluation (PCE): Perceptions and barriers to implementation
The College of Radiographers (CoR) 2013 policy and practice guidance identifies the ability to write Preliminary Clinical Evaluations (PCE) should be a core competency for radiographers. This research used a mixed methods approach to investigate the perceptions and potential barriers to the implementation of abnormality signalling systems (ASS) and in particular PCE in clinical practice.
A purposive sample of qualified radiographers from two NHS Trusts was identified (n = 62). Response rate was 90% (n=56).
20% (n=11) had been qualified 5years. Only 30% (n=17) felt that their university training prepared them well for PCE upon graduation however responses differed by group. 72% of those qualified 5 years qualified group are more likely to engage with CPD than the other groups. Only 23% (n=13) felt that PCE would improve service delivery stating lack of skill, guidance, 'too busy imaging', too much responsibility, and 'no pay increase', as common reasons. 70% (n=39) felt that PCE should not be implemented in practice.
The evidence suggests that the CoR 2013 policy is having an impact on undergraduate training in that the <2years qualified group are more responsive to delivering PCE but less likely to participate in CPD. Further work is required to measure graduate image interpretation competence and subsequent development
Preliminary clinical evaluation: The What/Where/How (WWH) approach to scoring.
The SCoR is driving for preliminary clinical evaluation (PCE) however; currently there is no method of quantification to assess quality. FRCR has an approach to quantify comments in the rapid reporting examination (CR2B).The aim of this project was to develop a robust scoring system that enables comprehensive image evaluation regardless of profession.
An image test bank was administered using RadBench with equal prevalence of normal /abnormal. A random sample of attempts was selected to pilot the scoring model. Sensitivity, specificity and accuracy were calculated. A scoring system (WWH) was developed based on the WHAT (fracture type), WHERE (location), HOW (displacement/angulation) concept (Harcus & Wright 2014) to evaluate the PCE. The results were compared to those obtained using the FRCR model.
Calculated actual mean accuracy, sensitivity and specificity scores were 87%, 80% and 93% respectively. FRCR scores were 88%, 80% and 97%. WWH scores were 65%, 37%, and 93%. The FRCR score appears to mirror the actual decision scores however it does not reflect the fact that the PCE for abnormal cases is often incomplete; 'What' 67%, 'Where' 87%, 'How' 7%.
The PCE score should ideally correlate with the actual score in order to provide useful information to the referring clinician. Whilst most comments state the location, less states the type, and very few refer to angulation or displacement. Analysis of the PCE is a useful indicator for targeting professional development. The sam
TGF-β mimic proteins form an extended gene family in the murine parasite Heligmosomoides polygyrus
We recently reported the discovery of a new parasite-derived protein that functionally mimics the immunosuppressive cytokine transforming growth factor (TGF)-β. The Heligmosomoides polygyrus TGF-β Mimic (Hp-TGM) shares no homology to any TGF-β family member, however it binds the mammalian TGF-β receptor and induces expression of Foxp3, the canonical transcription factor of both mouse and human regulatory T cells. Hp-TGM consists of five atypical Complement Control Protein (CCP, Pfam 00084) domains, each lacking certain conserved residues and 12–15 amino acids longer than the 60–70 amino acids consensus domain, but with a recognizable 3-cysteine, tryptophan, cysteine motif. We now report on the identification of a family of nine related Hp-TGM homologues represented in the secreted proteome and transcriptome of H. polygyrus. Recombinant proteins from five of the nine new TGM members were tested for TGF-β activity, but only two were functionally active in an MFB-F11 reporter assay, and by the induction of T cell Foxp3 expression. Sequence comparisons reveal that proteins with functional activity are similar or identical to Hp-TGM across the first three CCP domains, but more variable in domains 4 and 5. Inactive proteins diverged in all domains, or lacked some domains entirely. Testing truncated versions of Hp-TGM confirmed that domains 1–3 are essential for full activity in vitro, while domains 4 and 5 are not required. Further studies will elucidate whether these latter domains fulfill other functions in promoting host immune regulation during infection and if the more divergent family members play other roles in immunomodulation
MyD88 signaling inhibits protective immunity to the gastrointestinal helminth parasite heligmosomoides polygyrus
Helminth parasites remain one of the most common causes of infections worldwide, yet little is still known about the immune signaling pathways that control their expulsion. C57BL/6 mice are chronically susceptible to infection with the gastrointestinal helminth parasite Heligmosomoides polygyrus. In this article, we report that C57BL/6 mice lacking the adapter protein MyD88, which mediates signaling by TLRs and IL-1 family members, showed enhanced immunity to H. polygyrus infection. Alongside increased parasite expulsion, MyD88-deficient mice showed heightened IL-4 and IL-17A production from mesenteric lymph node CD4+ cells. In addition, MyD88-/- mice developed substantial numbers of intestinal granulomas around the site of infection, which were not seen in MyD88-sufficient C57BL/6 mice, nor when signaling through the adapter protein TRIF (TIR domain-containing adapter-inducing IFN-β adapter protein) was also ablated. Mice deficient solely in TLR2, TLR4, TLR5, or TLR9 did not show enhanced parasite expulsion, suggesting that these TLRs signal redundantly to maintain H. polygyrus susceptibility in wild-type mice. To further investigate signaling pathways that are MyD88 dependent, we infected IL-1R1-/- mice with H. polygyrus. This genotype displayed heightened granuloma numbers compared with wild-type mice, but without increased parasite expulsion. Thus, the IL-1R-MyD88 pathway is implicated in inhibiting granuloma formation; however, protective immunity in MyD88-deficient mice appears to be granuloma independent. Like IL-1R1-/- and MyD88-/- mice, animals lacking signaling through the type 1 IFN receptor (i.e., IFNAR1-/-) also developed intestinal granulomas. Hence, IL-1R1, MyD88, and type 1 IFN receptor signaling may provide pathways to impede granuloma formation in vivo, but additional MyD88-mediated signals are associated with inhibition of protective immunity in susceptible C57BL/6 mice
The secreted triose phosphate isomerase of Brugia malayi is required to sustain microfilaria production in vivo
Human lymphatic filariasis is a major tropical disease transmitted through mosquito vectors which take up microfilarial larvae from the blood of infected subjects. Microfilariae are produced by long-lived adult parasites, which also release a suite of excretory-secretory products that have recently been subject to in-depth proteomic analysis. Surprisingly, the most abundant secreted protein of adult Brugia malayi is triose phosphate isomerase (TPI), a glycolytic enzyme usually associated with the cytosol. We now show that while TPI is a prominent target of the antibody response to infection, there is little antibody-mediated inhibition of catalytic activity by polyclonal sera. We generated a panel of twenty-three anti-TPI monoclonal antibodies and found only two were able to block TPI enzymatic activity. Immunisation of jirds with B. malayi TPI, or mice with the homologous protein from the rodent filaria Litomosoides sigmodontis, failed to induce neutralising antibodies or protective immunity. In contrast, passive transfer of neutralising monoclonal antibody to mice prior to implantation with adult B. malayi resulted in 60–70% reductions in microfilarial levels in vivo and both oocyte and microfilarial production by individual adult females. The loss of fecundity was accompanied by reduced IFNγ expression by CD4+ T cells and a higher proportion of macrophages at the site of infection. Thus, enzymatically active TPI plays an important role in the transmission cycle of B. malayi filarial parasites and is identified as a potential target for immunological and pharmacological intervention against filarial infections
Macrophage migration inhibitory factor (MIF) is essential for Type 2 effector cell immunity to an intestinal helminth parasite
Immunity to intestinal helminths is known to require both innate and adaptive components of the immune system activated alongthe Type 2 IL-4R/STAT6-dependent pathway. We have found that macrophage migration inhibitory factor (MIF) is essential for thedevelopment of effective immunity to the intestinal helminth Heligmosomoides polygyrus, even following vaccination which inducessterile immunity in wild-type mice. A chemical inhibitor of MIF, 4-IPP, was similarly found to compromise anti-parasite immunity.Cellular analyses found that the adaptive arm of the immune response, including IgG1 antibody responses and Th2-derivedcytokines, was intact and that Foxp3+ T regulatory cell responses were unaltered in the absence of MIF. However, MIF was found tobe an essential cytokine for innate cells, with ablated eosinophilia and ILC2 responses, and delayed recruitment and activation ofmacrophages to the M2 phenotype (expressing Arginase 1, Chil3, and RΕLM‐alpha) upon infection of MIF‐deficient mice; amacrophage deficit was also seen in wild-type BALB/c mice exposed to 4-IPP. Gene expression analysis of intestinal and lymph nodetissues from MIF-deficient and -sufficient infected mice indicated significantly reduced levels of Arl2bp, encoding a factor involved innuclear localization of STAT3. We further found that STAT3-deficient macrophages expressed less Arginase-1, and that mice lackingSTAT3 in the myeloid compartment (LysMCrexSTAT3fl/fl) were unable to reject a secondary infection with H. polygyrus. We thusconclude that in the context of a Type 2 infection, MIF plays a critical role in polarizing macrophages into the protectivealternatively-activated phenotype, and that STAT3 signaling may make a previously unrecognized contribution to immunity tohelminths
Innate and adaptive type 2 immune cell responses in genetically controlled resistance to intestinal helminth infection
The nematode Heligmosomoides polygyrus is an excellent model for intestinal helminth parasitism. Infection in mice persists for varying lengths of time in different inbred strains, with CBA and C57BL/6 mice being fully susceptible, BALB/c partially so and SJL able to expel worms within 2–3 weeks of infection. We find that resistance correlates not only with the adaptive Th2 response, including IL-10 but with activation of innate lymphoid cell and macrophage populations. In addition, the titer and specificity range of the serum antibody response is maximal in resistant mice. In susceptible strains, Th2 responses were found to be counterbalanced by IFN-γ-producing CD4+ and CD8+ cells, but these are not solely responsible for susceptibility as mice deficient in either CD8+ T cells or IFN-γ remain unable to expel the parasites. Foxp3+ Treg numbers were comparable in all strains, but in the most resistant SJL strain, this population does not upregulate CD103 in infection, and in the lamina propria the frequency of Foxp3+CD103+ T cells is significantly lower than in susceptible mice. The more resistant SJL and BALB/c mice develop macrophage-rich IL-4Rα-dependent Type 2 granulomas around intestinal sites of larval invasion, and expression of alternative activation markers Arginase-1, Ch3L3 (Ym1) and RELM-α within the intestine and the peritoneal lavage was also strongly correlated with helminth elimination in these strains. Clodronate depletion of phagocytic cells compromises resistance of BALB/c mice and slows expulsion in the SJL strain. Thus, Type 2 immunity involves IL-4Rα-dependent innate cells including but not limited to a phagocyte population, the latter likely involving the action of specific antibodies
Concerted Activity of IgG1 Antibodies and IL-4/IL-25-Dependent Effector Cells Trap Helminth Larvae in the Tissues following Vaccination with Defined Secreted Antigens, Providing Sterile Immunity to Challenge Infection
Over 25% of the world's population are infected with helminth parasites, the majority of which colonise the gastrointestinal tract. However, no vaccine is yet available for human use, and mechanisms of protective immunity remain unclear. In the mouse model of Heligmosomoides polygyrus infection, vaccination with excretory-secretory (HES) antigens from adult parasites elicits sterilising immunity. Notably, three purified HES antigens (VAL-1, -2 and -3) are sufficient for effective vaccination. Protection is fully dependent upon specific IgG1 antibodies, but passive transfer confers only partial immunity to infection, indicating that cellular components are also required. Moreover, immune mice show greater cellular infiltration associated with trapping of larvae in the gut wall prior to their maturation. Intra-vital imaging of infected intestinal tissue revealed a four-fold increase in extravasation by LysM+GFP+ myeloid cells in vaccinated mice, and the massing of these cells around immature larvae. Mice deficient in FcRγ chain or C3 complement component remain fully immune, suggesting that in the presence of antibodies that directly neutralise parasite molecules, the myeloid compartment may attack larvae more quickly and effectively. Immunity to challenge infection was compromised in IL-4Rα- and IL-25-deficient mice, despite levels of specific antibody comparable to immune wild-type controls, while deficiencies in basophils, eosinophils or mast cells or CCR2-dependent inflammatory monocytes did not diminish immunity. Finally, we identify a suite of previously uncharacterised heat-labile vaccine antigens with homologs in human and veterinary parasites that together promote full immunity. Taken together, these data indicate that vaccine-induced immunity to intestinal helminths involves IgG1 antibodies directed against secreted proteins acting in concert with IL-25-dependent Type 2 myeloid effector populations