[The Evaluation of Left Ventricular Diastolic Function by Echocardiography in Patients With Preserved Ejection Fraction].

OBJECTIVE: to compare non-invasive evaluation of left ventricular (LV) diastolic function (DF) by echocardiography using algorithms of the 2009 and 2016 American Society of Echocardiography (ASE)/European Association of Echocardiography (EAE, now European Association of Cardiovascular Imaging [EACVI]) Recommendations. MATERIAL AND METHODS: The study included 100 patients with sinus rhythm and preserved left ventricular (LV) ejection fraction (EF). In all patients LV DF was assessed using both algorithms. In accordance with the ASE/EAE 2009 algorithm pulsed-wave tissue Doppler early diastolic velocity (e velocity) at lateral and septal basal regions of mitral annulus, as well as left atrial maximum volume index were evaluated. In accordance with the ASE/EACVI 2016 algorithm for judging the presence of LV diastolic dysfunction (DD), in addition to the two above-described criteria, E/e ratio and peak velocity of tricuspid regurgitation were analyzed. In the presence of 1 and more or equal 3 criteria LVDF was classified as normal and DD, respectively. If 2 criteria were detected result was considered as indeterminate. RESULTS: In 70% of patients in accordance with the ASE/EACVI 2016 algorithm DF was evaluated with 4 and in 100% - with 3 proposed criteria. The reason for using only 3 criteria was inadequate imaging of tricuspid regurgitation flow by continuous wave Doppler. Use of ASE/EACVI 2016 compared with the ASE/EAE 2009 algorithm in patients with normal LV EF led to a significant decrease of the number of patients with LV DD (13 vs. 27%, respectively; <0.05). The main reason for this redistribution was lowering of the cutoff value of annular e septal velocity from 8 (2009 algorithm) to 7 cm/sec (2016 algorithm). Frequency of indeterminate results with the use of 2016 algorithm was 2 times less than with the use of 2009 algorithm (15 vs. 36%, respectively; p<0.001). CONCLUSION: In patients with preserved LVEF the use of ASE/EACVI 2016 algorithm led to redistribution of data of evaluation of LVDF by echocardiography towards reduction of the number of patients with LV DD and with indeterminate results.

Plasmon-mediated magneto-optical transparency.

Magnetic field control of light is among the most intriguing methods for modulation of light intensity and polarization on sub-nanosecond timescales. The implementation in nanostructured hybrid materials provides a remarkable increase of magneto-optical effects. However, so far only the enhancement of already known effects has been demonstrated in such materials. Here we postulate a novel magneto-optical phenomenon that originates solely from suitably designed nanostructured metal-dielectric material, the so-called magneto-plasmonic crystal. In this material, an incident light excites coupled plasmonic oscillations and a waveguide mode. An in-plane magnetic field allows excitation of an orthogonally polarized waveguide mode that modifies optical spectrum of the magneto-plasmonic crystal and increases its transparency. The experimentally achieved light intensity modulation reaches 24%. As the effect can potentially exceed 100%, it may have great importance for applied nanophotonics. Further, the effect allows manipulating and exciting waveguide modes by a magnetic field and light of proper polarization.

Multicolor filter all-garnet magneto-optical photonic crystals.

We demonstrate a multicolor optical filter and isolator based on a double-cavity magneto-optical (MO) photonic crystal. Being grown as a heteroepitaxial all-garnet multilayer, it compromises a strong MO response and high optical transmittance. Low-loss, high Faraday rotation passbands as well as strong light rejection within the stop band were achieved by optimization of distance between cavities and repetition number of distributed Bragg reflectors.

[Using ultrasonography for detection of pulmonary extravascular fluid in patients with heart failure].

AIM: To study the possibilities of ultrasonography to detect abundant pulmonary fluid accumulation, by recording the ultrasound lung comets (ULCs). SUBJECTS AND METHODS: One hundred and forty coronary heart disease patients (aged 68.6 +/- 15.7 years) with signs of heart failure: acute left ventricular heart failure (acute left ventricular heart failure (ALVHF) in 19 patients and chronic heart failure (CHF) in 121, were examined. EchoCG, lung Xray study and ultrasonography (USG) were performed to reveal ULCs on admission and over time. RESULTS: On admission, lung USG recorded multiple ULCs in all patients (n = 15) in the ALVHF group. Repeated lung USG showed a decrease in the amount of ULCs in response to diuretic therapy. In the group of patients with Functional Classes (FC) III-IV CHF (n = 19), primary lung USG indicated multiple and single ULCs in 11 (57.9%). Repeated lung USG demonstrated a decrease in the amount of ULCs in response to diuretic therapy. In the FC I-II CHF (n = 106), primary lung ULCs identified multiple and single ULCs in 12 (11.3%). In the group of 19 apparently healthy individuals, single ULCs were revealed in 3 (15.8%) cases. CONCLUSION: The decreased number of ULCs in patients with CHF shows a high correlation with the efficiency of diuretic therapy. In patients with CHF, the detection rate of ULCs depends on the severity of CHF.

[Diagnosis of malignant pericardial mesothelioma].

Continuing growth of rate of detection of primary tumors of the heart has been noted recently. Prevalence of cardiac tumors in European population according to data of different authors varies from 25 to 5500 cases per 1 million of autopsies. Malignant mesothelioma belongs to most rarely met tumors. In most cases pericardial malignant mesothelioma possesses high secretory capacity what allows to suspect tumorous process in hemorrhagic pericarditis with recurrences after repetitive punctures. The paper contains description of a patient with malignant pericardial mesothelioma. Special feature of this case has been atypical clinical course of the disease complicated by development of acute myocardial infarction of posterior left ventricular wall.

Leu254 residue and calcium ions as new structural determinants of carboxypeptidase T substrate specificity.

New determinants of Thermoactinomyces vulgaris carboxypeptidase T (CPT) substrate specificity--structural calcium ions and Leu254 residue--were found by means of steady-state kinetics and site-directed mutagenesis. The removal of calcium ions shifted the selectivity profile of hydrolysis of tripeptide substrates with C-terminal Leu, Glu, and Arg from 64/1.7/1 to 162/1.3/1. Substitution of the hydrophobic Leu254 in CPT for polar Asn did not change hydrolysis efficiency of substrates with C-terminal Leu and Arg, but resulted in more than 28-fold decrease in activity towards the substrate with C-terminal Glu. It is shown that the His68 residue is not a structural determinant of CPT specificity.

Structural principles of the broad substrate specificity of Thermoactinomyces vulgaris carboxypeptidase T--role of amino acid residues at positions 260 and 262.

An influence of residues at positions 260 and 262 on a broad substrate specificity of Thermoactinomyces vulgaris carboxypeptidase T (CPT) has been studied by means of site-directed mutagenesis. The structure of the S1'-site of CPT is similar to those of pancreatic carboxypeptidases A (CPA) and B (CPB); however, the enzyme is capable of cleaving off C-terminal hydrophobic (like CPA), C-terminal positively charged (like CPB), and negatively charged residues. The spatial alteration of the S1' site hydrophobic area in CPT by an insertion of one residue in the active site loop with Tyr255 by analogy with CPA and CPB did not change the enzyme specificity. The introduction of Ile262 (CPT D260G/T262I) led to a statistically significant reduction in activity towards charged substrates. The removal of a negative (CPT D260G) and placement of a positive charge (CPT D260G/T262K and CPT D260G/T262R) in the S1' site shifted the specificity of the variants towards substrates with C-terminal Glu. The selectivity profile was 64:1.7:1 for wild-type CPT, 815:115:1 for CPT D260G, 3270:1060:1 for CPT D260G/T262K and 1:2.4:0 for CPT D260G/T262R for substrates with C-terminal Leu, Glu and Arg, respectively. The obtained results confirm the important role of the amino acid residues at positions 260 and 262 in determination of the CPT substrate specificity.

Structural principles of the wide substrate specificity of Thermoactinomyces vulgaris carboxypeptidase T. Reconstruction of the carboxypeptidase B primary specificity pocket.

Site-directed mutagenesis in the active site of Thermoactinomyces vulgaris carboxypeptidase T (CpT), which is capable of hydrolyzing both hydrophobic and positively charged substrates, resulted in five mutants: CpT1 (A243G), CpT2 (D253G/T255D), CpT3 (A243G/D253G/T255D), CpT4 (G207S/A243G/D253G/T255D), and CpT5 (G207S/A243G/T250A/D253G/T255D). These mutants step-by-step reconstruct the primary specificity pocket of carboxypeptidase B (CpB), which is capable of cleaving only positively charged C-terminal residues. All of the mutants retained the substrate specificity of the wild-type CpT. Based on comparison of three-dimensional structures of CpB and the CpT5 model, it was suggested that the lower affinity of CpT5 for positively charged substrates than the affinity of CpB could be caused by differences in nature and spatial location of Leu247 and Ile247 and of His68 and Asp65 residues in CpT and CpB, respectively, and also in location of the water molecule bound with Ala250. An additional hydrophobic region was detected in the CpT active site formed by Tyr248, Leu247, Leu203, Ala243, CH3-group of Thr250, and CO-groups of Tyr248 and Ala243, which could be responsible for binding hydrophobic substrates. Thus, notwithstanding the considerable structural similarity of CpT and pancreatic carboxypeptidases, the mechanisms underlying their substrate specificities are different.