Clinical outcomes of dexamethasone-eluting stent implantation in ST-elevation acute myocardial infarction.

OBJECTIVES: The aim of our study was to evaluate the safety and midterm clinical results of dexamethasone-eluting stent (DexES) implantation in ST-segment elevation acute myocardial infarction (STEMI). BACKGROUND: Inflammation plays a pivotal role in both inestabilization of coronary atherosclerotic plaques and development of restenosis after stent placement. Antiinflammatory agents may attenuate those mechanisms and improve clinical outcomes. There is little information about clinical results of DexES and no data are available about their utilization during percutaneous coronary intervention (PCI) in STEMI. METHODS: Consecutive patients with STEMI that underwent primary or rescue PCI in our institution were treated with DexES. Clinical follow-up with routine realization of noninvasive test for detection of myocardial ischemia and coronariography if necessary, were performed. The objective of the study was to evaluate the rate of MACE (death, reinfarction, or target lesion revascularization) during midterm follow-up. RESULTS: The procedure was successful in 96.7% of cases. There were no in-hospital deaths or reinfarctions. One acute stent thrombosis occurred and no subacute thrombosis were observed. During a mean follow-up period of 384 days, cardiac-related death was 1.1%, there were no reinfarctions or late stent thrombosis and target lesion revascularization rate was 4.2%. CONCLUSION: We conclude that utilization of DexES for PCI in STEMI is safe and provides good midterm clinical outcomes.     

A rapid method for electron beam energy check.

Assessment of electron beam energy and its long term stability is part of standard quality assurance practice in radiation oncology. Conventional depth-ionization or depth-film density measurements are time consuming both in terms of data acquisition and analysis. A procedure is described utilizing ionization measurements at two energy specific depths. It is based on a linear relationship between electron beam energy and its practical range. Energy shifts within the range covered by the two measurement depths are easily resolved. Within a range of +/- 0.50 MeV (+/- 1.30 MeV) around the established mean incident energy of 5.48 MeV (20.39 MeV), the method accuracy is better than 0.10 MeV.     

In situ activation of the type 2 ryanodine receptor in pancreatic beta cells requires cAMP-dependent phosphorylation

Molecular mechanisms that regulate in situ activation of ryanodine receptors (RY) in different cells are poorly understood. Here we demonstrate that caffeine (10 mM) released Ca²⁺ from the endoplasmic reticulum (ER) in the form of small spikes in only 14% of cultured fura-2 loaded beta cells from ob/ob mice. Surprisingly, when forskolin, an activator of adenylyl cyclase was present, caffeine induced larger Ca²⁺ spikes in as many as 60% of the cells. Forskolin or the phosphodiesterase-resistant PKA activator Sp-cAMPS alone did not release Ca²⁺ from ER. 4-Chloro-3-ethylphenol (4-CEP), an agent that activates RYs in other cell systems, released Ca²⁺ from ER, giving rise to a slow and small increase in [Ca²⁺]_i in beta cells. Prior exposure of cells to forskolin or caffeine (5 mM) qualitatively altered Ca²⁺ release by 4-CEP, giving rise to Ca²⁺ spikes. In glucose-stimulated beta cells forskolin induced Ca²⁺ spikes that were enhanced by 3,9-dimethylxanthine, an activator of RYs. Analysis of RNA from islets and insulin-secreting βTC-3-cells by RNase protection assay, using type-specific RY probes, revealed low-level expression of mRNA for the type 2 isoform of the receptor (RY₂). We conclude that in situ activation of RY₂ in beta cells requires cAMP-dependent phosphorylation, a process that recruits the receptor in a functionally operative form.     

Micro-Imaging by Interference Microscopy: A Case Study of Orientation-Dependent Guest Diffusion in MFI-Type Zeolite Host Crystals

Because of the small particle size, orientation-dependent diffusion measurements in microporous materials remains a challenging task. We highlight here the potential of micro-imaging by interference microscopy in a case study with MFI-type crystals in which, although with different accuracies, transient concentration profiles in all three directions can be observed. The measurements, which were performed with “rounded-boat” shaped crystals, reproduce the evolution patterns of the guest profiles recorded in previous studies with the more common “coffin-shaped” MFI crystals. The uptake and release patterns through the four principal faces (which in the coffin-shaped crystals extend in the longitudinal direction) are essentially coincident and there is no perceptible mass transfer in the direction of the long axis. The surface resistances of the four crystal faces through which mass transfer occurs are relatively small and have only a minor effect on the mass transfer rate. As a result of the pore structure, diffusion in the crystallographic c direction (which corresponds to the direction of the long axis) is expected to be much slower than in the transverse directions. This could explain the very low rate of mass transfer observed in the direction of the long axis, but it is also possible that the small end faces of the crystal may have high surface resistance. It is not possible to distinguish unequivocally between these two possibilities. All guest molecules studied (methyl-butane, benzene and 4-methyl-2-pentyne) show the same orientation dependence of mass transfer. The long 4-methyl-2-pentyne molecules would be expected to propagate at very different rates through the straight and sinusoidal channels. The coinciding patterns for uptake through the mutually perpendicular crystal faces therefore provide clear evidence that both the coffin shaped crystals and the rounded-boat-shaped crystals considered in this study, must be intergrowths rather than pure single crystals.     

Bleeding from gastrointestinal angioectasias is not related to bleeding disorders - a case control study

Background  

Angioectasias in the gastrointestinal tract can be found in up to 3% of the population. They are typically asymptomatic but may sometimes result in severe bleeding. The reasons for why some patients bleed from their angioectasias are not fully understood but it has been reported that it may be explained by an acquired von Willebrand syndrome (AVWS). This condition has similar laboratory findings to congenital von Willebrand disease with selective loss of large von Willebrand multimers. The aim of this study was to find out if AVWS or any other bleeding disorder was more common in patients with bleeding from angioectasias than in a control group.