Impact of transducer frequency setting on speckle tracking measures

Speckle tracking echocardiography is an emerging technique, which is currently being included in clinical guidelines. We sought to investigate the impact of transducer frequency settings on speckle tracking derived measures. The study comprised of 22 subjects prospectively enrolled for a randomized controlled trial (LOOP-study, Clinicaltrials.gov:NCT02036450). Patients were above 70 years of age with increased risk of stroke, and had an echocardiogram performed, which included focused images of the left ventricle. Focused images were obtained with the transducer frequency set at both 1.7/3.3 and 1.5/3.0 MHz. The images were obtained immediately after each other at the exact same position for the two settings. Speckle tracking was performed in three apical projections, allowing for acquisition of layered global longitudinal strain (GLS) and strain rate measures. Concordance between the frequency settings was tested for endo-, mid-, and epicardial GLS and strain rates by coefficients of variation, bias coefficients and visually displayed by Bland–Altman plots. Bland–Altman plots did not reveal any significant over- or underestimation of any speckle tracking measure. Bias coefficients showed that none of the measurements differed significantly between the two settings (bias for GLS_endo?=???0.07?±?2.94, p?=?0.91; GLS_mid?=?0.02?±?2.70, p?=?0.98, GLS_epi?=?0.07?±?2.53, p?=?0.90). Coefficients of variation were as follows: GLS_endo?=?15.11%, GLS_mid?=?15.28%, GLS_epi?=?17.26%, systolic strain rate?=?15.66%, early diastolic strain rate?=?38.46%, late diastolic strain rate?=?11%. Changing between transducer frequency settings does not systematically derange speckle tracking measures. One can safely reduce the transducer frequency without compromising the validity of speckle tracking derived measures.     

Regulation of NKG2D-ligand cell surface expression by intracellular calcium after HDAC-inhibitor treatment

In this study we demonstrate that histone deacetylase (HDAC)-inhibitor mediated cell surface expression of the structural different NKG2D-ligands MICA/B and ULBP2 is calcium-dependent. Treatment with the calcium chelator EGTA inhibited constitutive as well as HDAC-inhibitor induced MICA/B and ULBP2 cell surface expression on melanoma cells and Jurkat T-cells. A NKG2D-dependent cytolytic assay and staining with a recombinant NKG2D-Fc fusion protein showed that calcium chelation impaired the functional ability of NKG2D-ligands induced by HDAC-inhibitor treatment.The HDAC-inhibitor induced cell surface expression of ULBP2, but not MICA/B, was sensitive to treatment calmidazolium and trifluoperazine, two agents known to block calcium signaling. siRNA-mediated knock-down of the calcium-regulated proteins calmodulin or calpain did however not affect NKG2D-ligand cell surface expression on Jurkat T-cells. We further show that secretion and cell surface binding of the calcium-regulating protein galectin-1 is enhanced upon HDAC-inhibitor treatment of melanoma cells. However, binding of galectin-1 to cell surface glycoproteins was not critical for constitutive or HDAC-inhibitor induced MICA/B and ULBP2 cell surface expression.We provide evidence that MICA/B and ULBP2 cell surface expression is controlled differently by calcium, which adds to the increasing perception that cell surface expression of MICA/B and ULBP2 is controlled by distinct signal transduction pathways.     

Comparison of Rosco Neo-Sensitabs with Oxoid paper disks in EUCAST disk diffusion antimicrobial susceptibility testing on Mueller–Hinton agar

This study compared Neo-Sensitabs with Oxoid paper disks using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) disk diffusion antimicrobial susceptibility test on Mueller–Hinton agar. The EUCAST-recommended quality control strains (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212) (Part I) and clinical isolates (Part II) were investigated. In Part I of the study, 27 combinations of antimicrobial agents were tested on four quality control strains repeatedly up to 60 times and zone diameters of tablets and disks were compared. In Part II of the study, 351 clinical isolates were included to cover a broad range of species, as well as resistance mechanisms. In Part I, four major deviations (>1 mm outside quality control ranges) were observed with Neo-Sensitabs. In one case with P. aeruginosa ATCC 27853 (meropenem), there was a corresponding major deviation (2 mm) with the Oxoid disk. The three remaining major deviations with Neo-Sensitabs were observed with meropenem (2 mm) in E. coli ATCC 25922 and with ciprofloxacin (2 mm) and gentamicin (3 mm) in P. aeruginosa ATCC 27853. For Oxoid disks, there were only minor deviations (=1 mm outside quality control ranges) in these three cases. In Part II, there were six discrepancies, susceptible versus resistant, in 3,533 comparisons between the two methods with the clinical isolates. The Rosco Neo-Sensitabs appear to be a possible alternative to Oxoid paper disks for EUCAST disk diffusion antimicrobial susceptibility testing on Mueller–Hinton agar.     

Adrenergic effects on secretion of amylase from the rat salivary glands

The present study was undertaken to investigate the effect of adrenergic agents on secretion of amylase from the salivary glands in vivo. Saliva was collected from the distal oesophagus in conscious rats. Adrenaline increased the concentration of amylase in saliva and serum significantly. The result of infusion of alpha- and beta-adrenergic antagonists as well as noradrenaline and isoproterenol showed that secretion of salivary amylase is predominantly mediated by stimulation of beta-adrenergic receptors, especially of the beta 1-subtype. Investigation of the isoenzyme pattern in saliva, pancreatic juice and serum demonstrated that the major component in serum is salivary amylase. This study has shown that beta-adrenergic agents stimulate secretion of amylase from the salivary glands in rats. Though the secretion is mainly exocrine small amounts of amylase is found in serum, which seems to originate from the salivary glands.