Alginate coated biogenic silver nanoparticles for the treatment of Pseudomonas infections in rainbow trout.

Pseudomonas species are among the main pathogens causing rainbow trout infections. The present study provides a simple, green, sustainable, and rapid technique to synthesize of biogenic alginate-capped silver nanoparticles (Alg-Ag NPs) suitable for the treatment of Pseudomonas infections. It has been shown that the mechanism (aggregative or autocatalytic) of Alg-Ag NPs formation depended on Alg concentration and the heating approach used. The rate constants and activation energy were calculated. Alg-Ag NPs were characterized by UV-Vis, FTIR, XRD, TEM, AFM, XPS, and DLS. The optimal conditions for the fabrication of spherically-shaped (17-19 nm) and negatively-charged (zeta-potential <-50 mV) Alg-Ag NPs, which are stable during 9 months, included hot-plate assisted synthesis at 100 °C in diluted (1 mg/mL) Alg solutions. In vitro studies showed that Alg-Ag NPs exhibited prominent antimicrobial activity against collection Pseudomonas strains (inhibition zones ranged from 9.0 ± 1.0 to 19.0 ± 1.0 mm), with no significant loss of antibacterial efficacy after 9 months of storage. AFM analysis confirmed that the antibacterial effect of Alg-Ag NPs dealt with the direct nanomechanical disrupting of bacterial cells. The ability of Alg-Ag NPs to inhibit the growth of virulent P.aeruginosa, P.fluorescens and P. putida strains isolated from infected rainbow trout was evaluated. All tested strains were susceptible to Alg(10)-Ag NPs, while Alg(1)-Ag NPs demonstrated a limited strain-specific antibacterial effect. The obtained data displayed the prospects for the application of biogenic Alg-Ag NPs to create novel delivery systems for combating Pseudomonas infections in rainbow trout.

Study of complexation of single-stranded poly(rA) and poly(rU) with methylene blue.

To reveal the effect of DNA- or RNA-specific low-molecular compounds on cellular processes on the molecular level, we have carried out the studies with the application of spectroscopic methods. It is necessary for the understanding of structural-functional properties of nucleic acids in cell. In this work the interaction of DNA-specific thiazine dye methylene blue (MB) with synthetic polynucleotides poly(rA) and poly(rU) was studied. The interaction of MB with synthetic polyribonucleotides poly(rA) and poly(rU) was examined in the solution with high ionic strength in a wide phosphate-to-dye (P/D) range, using the absorption and fluorescence spectroscopies, as well as the fluorescence 2D spectra and 3D spectra analyses were given. Values of the fluorescence quenching constants for the complexes of MB with poly(rA) and poly(rU) were calculated (KSV is the Stern-Volmer quenching constant). Two different modes of MB binding to single-stranded (ss-) poly(rA) and poly(rU) and to their hybrid double-stranded (ds-) structure - poly(rA)-poly(rU) were identified. This ligand binds to ss-poly(rA) and poly(rA)-poly(rU) by semi-intercalation and electrostatic modes, but to ss-poly(rU) the prevailing mode is the electrostatic interaction.Communicated by Ramaswamy H. Sarma.

Management of Patients With Severe Mitral Annular Calcification: JACC State-of-the-Art Review.

Mitral annular calcification (MAC) is a common and challenging pathologic condition, especially in the context of an aging society. Surgical mitral valve intervention in patients with MAC is difficult, with varying approaches to the calcified annular anatomy, and the advent of transcatheter valve interventions has provided additional treatment options. Advanced imaging provides the foundation for heart team discussions and management decisions concerning individual patients. This review focuses on the prognosis of, preoperative planning for, and management strategies for patients with MAC.

Spectroscopic analysis of 2-(5-mercapto-1,3,4-oxadiazol-2-yl)-6-methylquinolin-4-ol binding to blood plasma albumin.

Binding of 2-(5-mercapto-1,3,4-oxadiazol-2-yl)-6-methylquinolin-4-ol (C1), a biologically active substance, to bovine blood plasma albumin (BSA) at 293, 298, and 303 K was studied using fluorescence (steady state, synchronous, excitation/emission matrix) and FT-IR spectroscopy methods. The experimental results showed that C1 causes fluorescence quenching of BSA through both static and dynamic quenching mechanisms. The thermodynamic parameters, enthalpy and entropy change, for the static quenching were calculated to be - 35.73 kJ mol-1 and - 35.34 J mol-1 K-1, which indicated that hydrogen bonding and van der Waals interactions were the predominant intermolecular forces regulating C1-BSA interactions. Distance between donor and acceptor (2.14, 2.26, and 2.30 nm) depending on the temperature, obtained from intrinsic Förster resonance energy transfer calculations, revealed the static quenching mechanism of BSA fluorescence in 0-3.0 × 10-5 mol/dm3 concentration range of C1. The micro-environmental and conformational changes in BSA structure, established by synchronous, excitation/emission matrices and FT-IR spectra showed the changes in the BSA secondary structure.

Sex Differences in Right Ventricular Systolic Function and All-Cause Mortality in Tricuspid Regurgitation.

INTRODUCTION: Sex differences have been poorly studied in patients with right-sided heart valve disease. The principal aim of the current study was to explore the impact of sex differences on right ventricular (RV) hemodynamics and all-cause mortality in patients with moderate or severe tricuspid regurgitation (TR). METHODS: This is a retrospective study of 209 patients with significant TR. All patients were clinically profiled at baseline and underwent a transthoracic echocardiogram. The cohort was followed up for clinical events for a median duration of 80 months (mean ± SD 69.4 ± 33.4 months). RESULTS: There were 117 women with a mean (± SD) age of 72.6 ± 13 years and 92 men with a mean (± SD) age of 70.8 ± 15.8 years. There were no sex differences between the individual measures of RV systolic function (tricuspid annular plane systolic excursion [TAPSE], systolic pulmonary artery pressure, and RV S'), but overall RV systolic dysfunction (TAPSE <16 mm and/or RV S' <10 cm/s) and left ventricular ejection fraction <50% were more common in men. Mean (± SD) RV wall tension (RV WT) was 3,170 ± 1,220 mm Hg × mm in women and 3,817 ± 1,499 mm Hg × mm in men (p = 0.002). There was no difference in all-cause mortality between women and men (Log-Rank p = 0.528). Age and increased RV WT were independent predictors of all-cause mortality both in women (hazard ratio [HR] 2.61) and men (HR 3.01). CONCLUSIONS: In this cohort of patients with significant TR, women more frequently had preserved RV systolic function than men. There was no sex-difference in all-cause mortality. An increased RV WT and higher age were independent predictors of all-cause mortality in both women and men.

Regional left ventricle scar detection from routine cardiac computed tomography angiograms using latent space classification.

OBJECTIVES: The aim of this study is to develop an automated method of regional scar detection on clinically standard computed tomography angiography (CTA) using encoder-decoder networks with latent space classification. BACKGROUND: Localising scar in cardiac patients can assist in diagnosis and guide interventions. Magnetic resonance imaging (MRI) with late gadolinium enhancement (LGE) is the clinical gold standard for scar imaging; however, it is commonly contraindicated. CTA is an alternative imaging modality that has fewer contraindications and is widely used as a first-line imaging modality of cardiac applications. METHODS: A dataset of 79 patients with both clinically indicated MRI LGE and subsequent CTA scans was used to train and validate networks to classify septal and lateral scar presence within short axis left ventricle slices. Two designs of encoder-decoder networks were compared, with one encoding anatomical shape in the latent space. Ground truth was established by segmenting scar in MRI LGE and registering this to the CTA images. Short axis slices were taken from the CTA, which served as the input to the networks. An independent external set of 22 cases (27% the size of the cross-validation set) was used to test the best network. RESULTS: A network classifying lateral scar only achieved an area under ROC curve of 0.75, with a sensitivity of 0.79 and specificity of 0.62 on the independent test set. The results of septal scar classification were poor (AUC < 0.6) for all networks. This was likely due to a high class imbalance. The highest AUC network encoded anatomical shape information in the network latent space, indicating it was important for the successful classification of lateral scar. CONCLUSIONS: Automatic lateral wall scar detection can be performed from a routine cardiac CTA with reasonable accuracy, without any scar specific imaging. This requires only a single acquisition in the cardiac cycle. In a clinical setting, this could be useful for pre-procedure planning, especially where MRI is contraindicated. Further work with more septal scar present is warranted to improve the usefulness of this approach.

Multimodality Imaging in Valvular Structural Interventions.

Structural valvular interventions have skyrocketed in the past decade with new devices becoming available and indications for patients who would previously have been deemed inoperable. Furthermore, while echocardiography is the main imaging tool and the first line for patient screening, cardiac magnetic resonance and CT are now essential tools in pre-planning and post-procedural follow-up. This review aims to address imaging modalities and their scope in aortic, mitral and tricuspid structural valvular interventions, including multimodality imaging. Pulmonary valve procedures, which are mostly carried out in patients with congenital problems, are discussed. This article presents a guide on individualised imaging approcahes on each of the available interventional procedures.

Automated Left Ventricle Ischemic Scar Detection in CT Using Deep Neural Networks.

Objectives: The aim of this study is to develop a scar detection method for routine computed tomography angiography (CTA) imaging using deep convolutional neural networks (CNN), which relies solely on anatomical information as input and is compatible with existing clinical workflows. Background: Identifying cardiac patients with scar tissue is important for assisting diagnosis and guiding interventions. Late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) is the gold standard for scar imaging; however, there are common instances where it is contraindicated. CTA is an alternative imaging modality that has fewer contraindications and is faster than Cardiovascular magnetic resonance imaging but is unable to reliably image scar. Methods: A dataset of LGE MRI (200 patients, 83 with scar) was used to train and validate a CNN to detect ischemic scar slices using segmentation masks as input to the network. MRIs were segmented to produce 3D left ventricle meshes, which were sampled at points along the short axis to extract anatomical masks, with scar labels from LGE as ground truth. The trained CNN was tested with an independent CTA dataset (25 patients, with ground truth established with paired LGE MRI). Automated segmentation was performed to provide the same input format of anatomical masks for the network. The CNN was compared against manual reading of the CTA dataset by 3 experts. Results: Note that 84.7% cross-validated accuracy (AUC: 0.896) for detecting scar slices in the left ventricle on the MRI data was achieved. The trained network was tested against the CTA-derived data, with no further training, where it achieved an 88.3% accuracy (AUC: 0.901). The automated pipeline outperformed the manual reading by clinicians. Conclusion: Automatic ischemic scar detection can be performed from a routine cardiac CTA, without any scar-specific imaging or contrast agents. This requires only a single acquisition in the cardiac cycle. In a clinical setting, with near zero additional cost, scar presence could be detected to triage images, reduce reading times, and guide clinical decision-making.

Clinical comparison of sub-mm high-resolution non-contrast coronary CMR angiography against coronary CT angiography in patients with low-intermediate risk of coronary artery disease: a single center trial.

BACKGROUND: The widespread clinical application of coronary cardiovascular magnetic resonance (CMR) angiography (CMRA) for the assessment of coronary artery disease (CAD) remains limited due to low scan efficiency leading to prolonged and unpredictable acquisition times; low spatial-resolution; and residual respiratory motion artefacts resulting in limited image quality. To overcome these limitations, we have integrated highly undersampled acquisitions with image-based navigators and non-rigid motion correction to enable high resolution (sub-1 mm3) free-breathing, contrast-free 3D whole-heart coronary CMRA with 100% respiratory scan efficiency in a clinically feasible and predictable acquisition time. OBJECTIVES: To evaluate the diagnostic performance of this coronary CMRA framework against coronary computed tomography angiography (CTA) in patients with suspected CAD. METHODS: Consecutive patients (n = 50) with suspected CAD were examined on a 1.5T CMR scanner. We compared the diagnostic accuracy of coronary CMRA against coronary CTA for detecting a ≥ 50% reduction in luminal diameter. RESULTS: The 50 recruited patients (55 ± 9 years, 33 male) completed coronary CMRA in 10.7 ± 1.4 min. Twelve (24%) had significant CAD on coronary CTA. Coronary CMRA obtained diagnostic image quality in 95% of all, 97% of proximal, 97% of middle and 90% of distal coronary segments. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were: per patient (100%, 74%, 55%, 100% and 80%), per vessel (81%, 88%, 46%, 97% and 88%) and per segment (76%, 95%, 44%, 99% and 94%) respectively. CONCLUSIONS: The high diagnostic image quality and diagnostic performance of coronary CMRA compared against coronary CTA demonstrates the potential of coronary CMRA as a robust and safe non-invasive alternative for excluding significant disease in patients at low-intermediate risk of CAD.

The clinical significance and prognostic value of right ventricular wall tension in moderate or severe tricuspid regurgitation.

Background: We aim to explore the determinants of right ventricular wall tension (RV base-to-apex length multiplied by systolic pulmonary artery pressure [RV WT] and association with all-cause mortality in patients with moderate-to-severe tricuspid regurgitation. Materials & methods: Of total, 180 patients (71 ± 15 years, 54% females) were included. An increased RV WT was defined as >3300 mmHg x mm. Results: Patients with increased RV WT (n = 85, 47%) were more likely to be male and taller than patients with normal RV WT. In a multivariable-adjusted model, increased RV WT was associated with a 2.6-fold higher risk of all-cause mortality (HR: 2.59, 95% CI: 1.65-4.06). Conclusion: In patients with significant tricuspid regurgitation, an increased RV WT was common, and associated with a 2.6-fold higher risk of all-cause mortality. Male sex was the only independent determinant.

The tricuspid annular plane systolic excursion to systolic pulmonary artery pressure index: Association with all-cause mortality in patients with moderate or severe tricuspid regurgitation.

BACKGROUND: In patients with significant tricuspid regurgitation (TR) the conventional markers for the assessment of right ventricular (RV) systolic function may be less accurate. Tricuspid annular plane systolic excursion (TAPSE) indexed to systolic pulmonary artery pressure (SPAP) (TAPSE/SPAP) may be prognostically useful in pulmonary hypertension and left ventricular dysfunction. Our aim was to explore its use in patients with moderate or severe TR. METHODS: A total of 209 patients (72 ± 14 years, 56% women) with moderate (n = 123) or severe (n = 86) TR (primary in 6% and secondary in 94%) were followed up for a median of 80 months (mean 70 ± 33 months). The clinical correlates of TAPSE/SPAP index and association with all-cause mortality were assessed. RESULTS: The TAPSE/SPAP index was inversely correlated with all-cause mortality with an optimal threshold of 0.49 mm/mmHg. A low index was found in 139 (68%) patients. In a multivariate Cox regression analysis adjusted for age, smoking, coronary artery disease, left ventricular ejection fraction, right atrium area and mitral valve replacement, low TAPSE/SPAP index was associated with significantly higher hazard ratio of all-cause mortality (HR: 2.07; 95% CI 1.32-3.27, p = .002). Age, coronary artery disease, left ventricular ejection fraction and right atrium area were other independent predictors of all-cause mortality. CONCLUSION: The TAPSE/SPAP index, reflecting RV systolic function in the longitudinal axis corrected for force generating by the RV is a powerful predictor of all-cause mortality in patients with moderate or severe TR.

Determinants and clinical significance of aortic stiffness in patients with moderate or severe aortic stenosis.

BACKGROUND: Patients with degenerative aortic stenosis (AS) are often older and have systemic hypertension and atherosclerosis, which all lead to increased aortic stiffness. We aimed to assess the determinants of carotid-femoral pulse wave velocity (cf-PWV), a direct measure of aortic stiffness, and its association with revealed symptoms and clinical outcome in patients with AS. METHODS: We included 103 asymptomatic patients aged 66.6 ± 13.2 years (range 27-85 years, 69% males) with moderate (n = 50) and severe (n = 53) AS. All underwent a comprehensive echocardiography, exercise treadmill test (ETT) and assessment of aortic stiffness derived from cf-PWV by applanation tonometry. RESULTS: The mean cf-PWV was 10.6 ± 3.1 m/s and resting brachial blood pressure (BP) 139 ± 20/79 ± 11 mmHg. Increased cf-PWV (≥10 m/s) was found in 44% (n = 45) patients. Patients with moderate and severe AS had a similar degree of aortic stiffness (cf-PWV 10.7 ± 3.3 vs. 10.5 ± 3.0 m/s, p = 0.698). In a univariate logistic regression analysis, higher cf-PWV was not associated with revealed symptoms (odds ratio [OR] for 1SD higher cf-PWV 1.12; 95% CI 0.62-2.04, p = 0.706). In a multivariable linear regression analysis, age, resting brachial systolic BP and diabetes were associated with higher cf-PWV independent of antihypertensive treatment and left ventricular ejection fraction. The event-free survival was significantly lower in patients with cf-PWV ≥10 m/s compared to those with cf-PWV <10 m/s (p = 0.015). CONCLUSION: Increased cf-PWV was common in patients with moderate or severe AS, and was associated with higher cardiovascular disease burden and impaired prognosis. cf-PWV did not correlate with the severity of AS or the frequencies of revealed symptoms by ETT.

Impact of pulmonary hypertension on outcome in patients with moderate or severe tricuspid regurgitation.

Objectives: The true prevalence and disease burden of moderate or severe (significant) tricuspid regurgitation (TR) in patients undergoing routine echocardiography remains unknown. Our aim was to explore the prevalence of significant TR and the impact of pulmonary hypertension (PH) on outcome in a less selected cohort of patients referred to echocardiography. Methods: From 12 791 echocardiograms performed between January and December 2010, a total of 209 (1.6%) patients (72±14 years, 56% men) were identified with significant TR; 123 (0.96%) with moderate and 86 (0.67%) with severe TR. Median follow-up time was 80 months (mean 70±33 months). Systolic pulmonary artery pressure was derived from peak velocity of tricuspid regurgitant jet plus the right atrial pressure and considered elevated if ≥40 mm Hg (PH). Results: During follow-up there were 123 (59%) deaths with no difference in mortality between moderate and severe TR (p=0.456). The death rates were 93 (67%) in patients with PH versus 30 (42%) without PH (p<0.001). PH was associated with lower event-free survival in moderate (log-rank, p<0.001), but not in severe TR (log-rank, p=0.133). In a multivariate Cox regression analysis adjusted for age, smoking, coronary artery disease, reduced right ventricle S', lower left ventricular ejection fraction at baseline, right atrium size and mitral valve replacement, PH remained a significant predictor of all-cause mortality (HR 2.22; 95% CI 1.41 to 3.47, p=0.001). Conclusions: Moderate or severe TR was found in 1.6% of patients attending for routine echocardiograms. PH identified a high-risk subset of patients with moderate TR but not with severe TR.

Synthesis of Carvone-Derived 1,2,3-Triazoles Study of Their Antioxidant Properties and Interaction with Bovine Serum Albumin.

Natural L-carvone was utilized as a starting material for an efficient synthesis of some terpenyl-derived 1,2,3-triazoles. Chlorination of carvone, followed by nucleophilic substitution with sodium azide resulted in the preparation of 10-azidocarvone. Subsequent CuAAC click reaction with propargylated derivatives provided an efficient synthetic route to a set of terpenyl-derived conjugates with increased solubility in water. All investigated compounds exhibit high antioxidant activity, which is comparable with that of vitamin C. It was also found that serum albumin and the terpenyl-1,2,3-triazoles hybrids spontaneously undergo reversible binding driven by hydrophobic interactions, suggesting that serum albumin can transport the target triazoles.

Effect of diethylsulfoxide on the thermal denaturation of DNA.

DNA thermal denaturation has been investigated in aqueous solutions of diethylsulfoxide (DESO) by means of UV-vis and densimetry methods. It is suggested that, on the one hand, the structural change of entire solutions and, on the other hand, a direct interaction of DESO with DNA are responsible for the observed peculiar behavior. The results obtained were compared with those of dimethylsulfoxide (DMSO), also known from literature.

Increasing breastfeeding rates in New York City, 1980-2000.

Our objective was to determine temporal patterns of breastfeeding among women delivering infants in New York City (NYC) and compare national breastfeeding trends. All hospitals in NYC with obstetric units were contacted in May and June 2000 to provide information on the method of infant feeding during the mother's admission for delivery. Feeding was categorized as "exclusive breastfeeding," "breast and formula," or "exclusive formula." The first two categories were further grouped into "any breastfeeding" in the analysis. Hospitals were classified as "public" and "private," and patients were classified by insurance type as "service" and "private." Data between public and private hospitals and service and private patients were compared. Breast-feeding trends over time were compared by using previous iterations of the same survey. Of 16,932 newborns, representing approximately 80.0% of all reported live births in the city during the study period, 5,305 (31.3%) were exclusively breastfed, 6,189 (36.6%) were fed a combination of breast milk and formula, and the remaining 5,438 (32.1%) were exclusively formula-fed. Infants born in private hospitals were 1.6 times more likely to be exclusively breastfed compared with infants discharged from public hospitals (33% vs. 21%, respectively). Similarly, private patients were more likely than service patients to exclusively breastfeed their infants (39.6% vs. 22.9%, respectively) and to use a combination of breast and formula (i.e., any breastfeeding) (73.6% vs. 62.0%, respectively). From 1980 to 2000, the proportion of exclusive breastfeeding increased from 25.0% to 31.0%, the percentage of combined feeding increased from 8.0% to 37.0%, and the percentage of any breastfeeding increased from 33.0% to 68.0%. NYC has more than doubled the rate of breastfeeding since 1980. However, there is much progress to be made, and continued efforts are vital to maintain current gains in breastfeeding, improve the rates further, and prolong the duration of breastfeeding.