Burn-associated delayed dilated cardiomyopathy evaluated by cardiac PET and SPECT: Report of a case

AbstractDilated cardiomyopathy is a delayed-onset and rarely reported cardiac complication of burn injury although the mechanism remains unclear. We thus report a case of dilated cardiomyopathy following severe burn injury, in which technetium 99m sestamibi single-photon emission computed tomography (SPECT), iodine-123 beta-methyl-iodophenylpentadecanoic acid SPECT and 18F-fluorodeoxyglucose positron emission tomography (PET) were performed to evaluate the pathophysiologic condition in combination with cardiac catheterization and myocardial biopsy. The cardiac PET and SPECT images showed reduced myocardial blood flow, decreased fatty acid metabolism, and increased glucose utilization in the left ventricular lateral wall in spite of normal coronary angiography, no significant cardiac fibrosis, and inflammatory cell infiltration, which suggests that myocardial ischemia due to microcirculatory disturbance in hypermetabolic state associated with burn injury might be a causative mechanism of dilated cardiomyopathy in this case. A beta blocker, bisoprolol, was successfully introduced in this patient in combination with oral inotropic agents, pimobendan and digitalis after the prolonged use of intravenous dobutamine infusion, which might have been beneficial for this patient with burn-associated dilated cardiomyopathy not only to reduce regional myocardial ischemia but also to attenuate hypermetabolic state after severe burn injury.<Learning objective: Dilated cardiomyopathy complicated with burn injury has been reported to cause a sudden attack of dyspnea and death. This case report suggests that burn-associated dilated cardiomyopathy may be caused by relative myocardial ischemia due to microvascular disturbance in hypermetabolic state associated with burn injuries and can be treated effectively with beta blockers with or without oral inotropic agents.

Biocompatible fluorescent silicon nanocrystals for single-molecule tracking and fluorescence imaging.

Fluorescence microscopy is used extensively in cell-biological and biomedical research, but it is often plagued by three major problems with the presently available fluorescent probes: photobleaching, blinking, and large size. We have addressed these problems, with special attention to single-molecule imaging, by developing biocompatible, red-emitting silicon nanocrystals (SiNCs) with a 4.1-nm hydrodynamic diameter. Methods for producing SiNCs by simple chemical etching, for hydrophilically coating them, and for conjugating them to biomolecules precisely at a 1:1 ratio have been developed. Single SiNCs neither blinked nor photobleached during a 300-min overall period observed at video rate. Single receptor molecules in the plasma membrane of living cells (using transferrin receptor) were imaged for ≥10 times longer than with other probes, making it possible for the first time to observe the internalization process of receptor molecules at the single-molecule level. Spatial variations of molecular diffusivity in the scale of 1-2 µm, i.e., a higher level of domain mosaicism in the plasma membrane, were revealed

Successful Treatment of Pulmonary Arterial Hypertension in Systemic Sclerosis with Anticentriole Antibody

Systemic sclerosis (SSc) is characterized by skin sclerosis and multiple organ damages which may cause mortality and is usually accompanied with several specific autoantibodies, each of which is associated with characteristic complications. Among them, anticentriole antibody is recently reported to be highly associated with SSc-associated pulmonary arterial hypertension (SSc-PAH). In general, several vasodilators are used as therapeutic drugs for SSc-PAH, whereas immunosuppressive therapies are not. Here, we report the case of a 62-year-old female with anticentriole antibody-positive SSc-PAH treated with immunosuppressants and vasodilators. She presented with two-year exertional dyspnea and was diagnosed with PAH and SSc owing to the centriole staining pattern and other symptoms without digital sclerosis. Oral vasodilators were initially administered but were not sufficiently effective on dyspnea. Immunosuppressants such as prednisolone and cyclophosphamide were started. Both of them improved mean pulmonary arterial pressure and 6-minute walk distance, and the anticentriole antibody also disappeared. In this case, SSc-PAH with anticentriole antibody was properly diagnosed and immunosuppressants and vasodilators improved the hemodynamics of PAH with anticentriole antibody and stably maintained it and, in addition, reduced the titer of anticentriole antibody. This indicates that anticentriole antibody might represent a good responsive group to therapies among subgroups of patients with SSc-PAH

Nature of the Volume Isotope Effect in Ice

he substitution of hydrogen (H) by deuterium (D) in ice Ih and in its H-ordered version, ice XI, produces an anomalous form of volume isotope effect (VIE), i.e., volume expansion. This VIE contrasts with the normal VIE (volume contraction) predicted in ice-VIII and in its H-disordered form, ice VII. Here we investigate the VIE in ice XI and in ice VIII using first principles quasiharmonic calculations. We conclude that normal and anomalous VIEs can be produced in ice VIII and ice XI in sequence by application of pressure (ice XI starting at negative pressures) followed by a third type-anomalous VIE with zero-point volume contraction. The latter should also contribute to the isotope effect in the ice VII -> ice X transition. The predicted change between normal and anomalous VIE in ice VIII at 14.3 GPa and 300 K is well reproduced experimentally in ice VII using x-ray diffraction measurements. The present discussion of the VIE is general, and conclusions should be applicable to other solid phases of H2O, possibly to liquid water under pressure, and to other H-bonded materials