A survey investigating postero-anterior chest X-ray clinical technique amongst radiographers and assistant practitioners in the UK: An extended pilot study.

INTRODUCTION: Whilst many technical factors for the postero-anterior (PA) chest projection are well-researched and standardised, anecdotal evidence suggests a discrepancy regarding positioning of the X-ray tube; some radiographers using a horizontal tube, and others apply an angle. Currently there is a lack of published evidence supporting the benefits of either technique. METHODS: Following University ethical approval, an invitation e-mail containing a link to a short questionnaire and participant information sheet was sent to radiographers and assistant practitioners in Liverpool and the surrounding areas, via professional networks/research team contacts. Questions related to length of experience, highest qualification and reasoned choice of horizontal versus angled tube preference in Computed Radiography (CR) and Digital Radiography (DR) rooms. The survey was open for nine weeks, with reminders at five and eight weeks. RESULTS: There were 63 respondents. Both techniques were commonplace, with a non-statistically significant preference (p = 0.439) for a horizontal tube in both DR rooms (59%, n = 37) and CR rooms (52%, n = 30). Angled technique was employed by 41% (n = 26) of participants in DR rooms and 48% (n = 28) in CR rooms. Many participants indicated 'taught', or 'protocol', influenced their approach (46% [n = 29] in DR, 38% [n = 22] in CR). 35% (n = 10) of participants using caudal angulation, identified dose optimisation as the rationale in both CR and DR rooms. Most specifically noted reduced dose to the thyroid (69% [n = 11] in CR, 73% [n = 11] in DR). CONCLUSIONS: There is evidence of variation in practice regarding horizontal versus an angled X-ray tube but no consistent rationale for either choice. IMPLICATIONS FOR PRACTICE: There is a need to standardise tube positioning in PA chest radiography in line with future empirical research into the dose-optimisation implications of tube angulation.

The use of videofluoroscopy (VFS) and fibreoptic endoscopic evaluation of swallowing (FEES) in the investigation of oropharyngeal dysphagia in stroke patients: A narrative review.

OBJECTIVES: Patients with suspected acute stroke require rapid assessment of swallowing on admission. If aspiration is suspected, this takes the form of specialist assessment, using either videofluoroscopy (VFS) or fibreoptic endoscopic evaluation of swallowing (FEES). The review aim was to evaluate and compare the effectiveness of each method in stroke patients. Literature was collected from the databases Scopus, Web of Science and Medline, and articles included in the review were published within the last 10 years, in the English language. KEY FINDINGS: Sensitivity and specificity ranged from 0.29-0.33 and 0.96-1.0 for VFS, respectively, and 0.37-1.0 and 0.65-0.87 for FEES, respectively, depending on the type of bolus utilised. VFS is the current gold-standard for the investigation of oropharyngeal dysphagia (OD), however, radiation dose and patient transport implications mean FEES may be preferred. FEES has limitations including 'whiteout' and the invasive nature of the endoscope. The NICE guidelines do not recommend a definitive protocol specifically in stroke patients. This suggests further research may be required to determine the most effective method. CONCLUSION: FEES is a beneficial first line examination, providing limited invasiveness, and administering a high level of patient suitability, without using ionising radiation. VFS could potentially be useful following FEES to secure full visualisation, ensuring an aspiration event is not missed during FEES. IMPLICATIONS FOR PRACTICE: Use of FEES as the first line test rather than VFS, ensures radiation dose is as low as reasonably practicable (ALARP). Ongoing research to ensure protocols follow current best practice can help ensure accurate management of oropharyngeal dysphagia in stroke patients.

Design and synthesis of some substrate analogue inhibitors of phospholipase A2 and investigations by NMR and molecular modeling into the binding interactions in the enzyme-inhibitor complex.

A series of substrate analogue inhibitors of pancreatic phospholipase A2 has been designed and synthesized. The compounds were tested in a novel dual-screening system based on parallel assays with monomeric and micellar substrates. Intermolecular nuclear Overhauser effects between vinylic protons on one inhibitor and identified active site residues on the bovine pancreatic enzyme have been observed in solution NMR studies of the enzyme-inhibitor complex. It can be deduced from both the biochemical results and the NMR data that the mode of interaction between this type of inhibitor and the active site of phospholipase A2 is essentially the same, irrespective of the presence or absence of an aggregated phospholipid surface. A model of the binding between the enzyme and inhibitor which incorporates the two-dimensional NMR data has been developed. The model can account for the activity of modified inhibitor structures and can be extrapolated to an assessment of the mode of binding of the natural substrate itself.

Design, synthesis, and physicochemical properties of a novel, conformationally restricted 2,3-dihydro-1,3,4-thiadiazole-containing angiotensin converting enzyme inhibitor which is preferentially eliminated by the biliary route in rats.

Two novel series of dihydrothiadiazole ring containing inhibitors of angiotensin converting enzyme have been designed and synthesized. The compounds are highly potent enzyme inhibitors and, as a consequence of conformational restriction, chemically stable with respect to undesirable cyclization reactions. The most interesting compound from this series, 5a (FPL 63547), is the monoethyl ester prodrug of the highly potent "aminocarboxy" inhibitor 5b (FPL 63674). It produces an antihypertensive effect of long duration in animal models after oral dosing. Unlike other ACE inhibitors, 5b is eliminated almost entirely by biliary clearance in the rat. The favorable pharmacological properties of 5a and 5b are rationalized in terms of their unique physicochemical profiles. The clear preference for biliary clearance seen with 5b is consistent with its lipophilicity and its high degree of net ionization at physiological pH, which results from the very low pKa of the C-terminus carboxylic acid function. FPL 63547 is presently undergoing clinical investigation in man.