A narrative review on pain control interventions for non-surgical pleural procedures.

Pleural diseases are common and frequently result in disabling symptoms, impaired health-related quality of life and hospitalisation. Both diagnosis and management often require pleural procedures and despite a variety of pain control strategies available for clinicians to employ, many procedures are still complicated by pain and discomfort. This can interfere with procedure success and can limit patient satisfaction. This review examines the evidence for pain control strategies for people undergoing non-surgical pleural procedures. A systematic literature search was undertaken to identify published studies examining different pain control strategies including pharmacological (sedatives, paravertebral blocks, erector spinae blocks, intrapleural anaesthesia, epidural anaesthesia, local anaesthetic, methoxyflurane, non-steroidal anti-inflammatory drugs [NSAIDs], opioids) and non-pharmacological measures (transcutaneous electric nerve stimulation [TENS], cold application and changes to the intervention or technique). Current literature is limited by heterogeneous study design, small participant numbers and use of different endpoints. Strategies that were more effective than placebo or standard care at improving pain included intrapleural local anaesthesia, paravertebral blocks, NSAIDs, small-bore intercostal catheters (ICC), cold application and TENS. Inhaled methoxyflurane, thoracic epidural anaesthesia and erector spinae blocks may also be useful approaches but require further evaluation to determine their roles in routine non-surgical pleural procedures. Future research should utilise reliable and repeatable study designs and reach consensus in endpoints to allow comparability between findings and thus provide the evidence-base to achieve standardisation of pain management approaches.

Downmodulation of Effector Functions in NK Cells upon Toxoplasma gondii Infection.

The obligate intracellular parasite Toxoplasma gondii can actively infect any nucleated cell type, including cells from the immune system. The rapid transfer of T. gondii from infected dendritic cells to effector natural killer (NK) cells may contribute to the parasite's sequestration and shielding from immune recognition shortly after infection. However, subversion of NK cell functions, such as cytotoxicity or production of proinflammatory cytokines, such as gamma interferon (IFN-γ), upon parasite infection might also be beneficial to the parasite. In the present study, we investigated the effects of T. gondii infection on NK cells. In vitro, infected NK cells were found to be poor at killing target cells and had reduced levels of IFN-γ production. This could be attributed in part to the inability of infected cells to form conjugates with their target cells. However, even upon NK1.1 cross-linking of NK cells, the infected NK cells also exhibited poor degranulation and IFN-γ production. Similarly, NK cells infected in vivo were also poor at killing target cells and producing IFN-γ. Increased levels of transforming growth factor ß production, as well as increased levels of expression of SHP-1 in the cytosol of infected NK cells upon infection, were observed in infected NK cells. However, the phosphorylation of STAT4 was not altered in infected NK cells, suggesting that transcriptional regulation mediates the reduced IFN-γ production, which was confirmed by quantitative PCR. These data suggest that infection of NK cells by T. gondii impairs NK cell recognition of target cells and cytokine release, two mechanisms that independently could enhance T. gondii survival.

Ligand-supported purification of the urotensin-II receptor.

A crucial limitation for structural and biophysical analysis of G protein-coupled receptors (GPCRs) is the inherent challenge of purifying and stabilizing these receptors in an active (agonist-bound) conformation. Peptide ligands, such as the vasoactive, cyclic hormone urotensin-II (U-II), may provide new purification tools, via high affinity, pseudo-irreversible binding suitable for ligand-based affinity purification. We show that the U-II receptor (UT) is resistant to desensitization as a result of low phosphorylation and diminished endocytosis. UT also displays an unusual proclivity to remain active with vasoconstriction sustained despite extensive washout of the ligand. To exploit these properties for ligand-supported purification, we modified the U-II ligand by attaching a biotin moiety and spacer arm to the N terminus, creating a novel affinity ligand (Bio-U-II) to interface with streptavidin media. Bio-U-II bound to UT with pharmacological properties analogous to those of the unmodified U-II ligand (high-affinity, pseudo-irreversible binding). The prebinding of Bio-U-II to UT (before exposure to detergent) facilitated specific capture of UT by stabilizing the receptor structure during solubilization with detergent. Solubilization of UT with the most compatible detergent, n-dodecyl ß-d-maltoside, was dependent on the critical micelle concentration, and Gα(q/11) protein was copurified with captured Bio-U-II-UT complexes. Furthermore, captured Bio-U-II-UT complexes were resistant to dissociation at elevated temperatures, suggesting that UT is relatively thermostable, making it an ideal candidate for future structural and biophysical studies. This work demonstrates the utility of pseudo-irreversible ligands to support the purification of a GPCR during detergent extraction, resulting in the first successful purification of the UT.