Accuracy of Point-of-Care-Ultrasonography in Confirming Shoulder Reduction in Emergency Departments

Aims Accurate identification of the successful reduction of a dislocated shoulder could avoid additional episodes of procedural sedation and repeated performance of X-rays. The objective of this study was to assess the diagnostic accuracy of point-of-care-ultrasound (POCUS) in the confirmation of a successful joint reduction in patients with shoulder dislocation. Methods This was a single-centre, prospective observational study set in an urban academic ED in Ireland, with a convenience sample of adult patients with shoulder dislocation on X-ray. Ultrasound was performed on participants before and after joint reduction using a posterior approach technique. The operator's confidence levels were recorded after image acquisition. Results Thirty-three subjects were recruited. All dislocations were correctly identified on pre-reduction US, indicating a sensitivity of 100% (CI 89.42 - 100). Post-reduction US confirmed successful reduction in 30 subjects that were subsequently reported as such on X-Ray, giving it a specificity of 100% (CI 88.43 - 100). Failure to achieve reduction was correctly identified on US in three cases, resulting in post-reduction US Sensitivity of 100% (CI 29.24 - 100) and 100% accuracy (CI 89.42 - 100). Conclusion This study has shown that POCUS, with a posterior approach technique, has 100% sensitivity and specificity in confirming successful shoulder reduction in the ED.

DVT presentations to an Emergency Department: A study of guideline based care and decision making

Pre-test probability scoring and blood tests for deep venous thrombosis (DVT) assessment are sensitive but not specific leading to increased demands on radiology services. 385 patients presenting to an Emergency Department with suspected DVT were studied to explore our actual work up of patients with possible DVT relating to risk stratification, further investigation and follow up. Of the 205 patients with an initially negative scan, 36 (17.6%) were brought for review to the Emergency Department Consultant clinic. 34 (16.6%) patients underwent repeat compression ultrasound with 5 (2.4%) demonstrating a DVT on the second scan. Repeat compression ultrasound scans were performed on 34 (16.6%) of patients with an initially negative scan with essentially the same diagnostic yield as other larger studies where 100% of such patients had repeat scanning. Where there is ongoing concern, repeat above knee compression ultrasound within one week will pick up a small number of deep venous thromboses.

miR-182 and miR-10a are key regulators of Treg specialisation and stability during Schistosome and Leishmania-associated inflammation

A diverse suite of effector immune responses provide protection against various pathogens. However, the array of effector responses must be immunologically regulated to limit pathogen- and immune-associated damage. CD4⁺Foxp3⁺ regulatory T cells (Treg) calibrate immune responses; however, how Treg cells adapt to control different effector responses is unclear. To investigate the molecular mechanism of Treg diversity we used whole genome expression profiling and next generation small RNA sequencing of Treg cells isolated from type-1 or type-2 inflamed tissue following Leishmania major or Schistosoma mansoni infection, respectively. In-silico analyses identified two miRNA “regulatory hubs” miR-10a and miR-182 as critical miRNAs in Th1- or Th2-associated Treg cells, respectively. Functionally and mechanistically, in-vitro and in-vivo systems identified that an IL-12/IFNγ axis regulated miR-10a and its putative transcription factor, Creb. Importantly, reduced miR-10a in Th1-associated Treg cells was critical for Treg function and controlled a suite of genes preventing IFNγ production. In contrast, IL-4 regulated miR-182 and cMaf in Th2-associed Treg cells, which mitigated IL-2 secretion, in part through repression of IL2-promoting genes. Together, this study indicates that CD4⁺Foxp3⁺ cells can be shaped by local environmental factors, which orchestrate distinct miRNA pathways preserving Treg stability and suppressor function.

The diversity of pathogens that the immune system encounters are controlled by a diverse suite of immunological effector responses. Preserving a well-controlled protective immune response is essential. Too vigorous an effector response can be as damaging as too little. Regulatory T cells (Treg) calibrate immune responses; however, how Treg cells adapt to control the diverse suite of effector responses is unclear. In this study we investigated the molecular identity of regulatory T cells that control distinct effector immune responses against two discrete pathogens, an intracellular parasitic protozoa, Leishmania major, and an extracellular helminth parasite, Schitsosoma mansoni. The two Treg populations studied were phenotypically and functionally different. We identified molecular pathways that influence this diversity and more specifically, we identified that two miRNAs (miR-182 and miR-10a) act as “regulatory hubs” critically controlling distinct properties within each Treg population. This is the first study identifying the upstream molecular pathways controlling Treg cell specialization and provides a new platform of Treg cell manipulation to fine-tune their function.