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Abstract: Background: The differential diagnosis of cardiac myxomas (CM), the most common benign primary cardiac tumors, is broad and a thorough diagnostic workup is required to establish accurate diagnosis prior to surgical resection. Transthoracic echocardiography (TTE) is usually the first imaging modality used for diagnosis of suspected CM. In a single tertiary centre study, we sought to determine the accuracy, sensitivity, and specificity of TTE in the diagnosis of CM and to determine echocardiographic characteristics indicative of CM. Patients and methods: We retrospectively analyzed clinical, echocardiographic, and pathohistological findings of 73 patients consecutively admitted for suspected CM. Results: After diagnostic workup, 53 (73%) patients were treated surgically at our institution. Based on preoperative TTE, patients were divided into a CM group (n=45, 85%) and non-myxoma (NM) group. Of the 53 pathohistological specimens obtained during surgery, 39 (73%) were CM. The sensitivity and specificity of preoperative echocardiography were 97% and 50%, respectively. The overall accuracy was 85%. All NM tumors were found in an atypical location and 72% of CM were found in a typical position in the left atrium (p < 0.001). Tumors in NM group were significantly smaller than CM (24.3 ± 13.2 mm vs. 37.9 ± 18.3 mm, p = 0.017). Conclusions: Our study confirms very good accuracy of TTE in the diagnosis of CM. The most important echocardiographic characteristics to differentiate between CM and tumors of different etiology are tumor location and size. Smaller tumors presenting at an atypical location are less likely to be diagnosed as CM, and these require additional imaging modalities for accurate diagnosis.
Keywords: cardiac mass, cardiac myxoma, cardiovascular imaging, echocardiography
Published in DiRROS: 16.12.2025; Views: 0; Downloads: 0
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Abstract: Purpose: Effective intercellular communication among lens epithelial cells (LECs) is essential for lens homeostasis, and its disruption has been implicated in cataract formation. This study investigates the mechanisms of calcium (Ca²⁺) wave propagation in the human lens epithelium, focusing on the respective roles of gap-junctional coupling and ATP-mediated paracrine signaling. Methods: We performed multicellular Ca²⁺ imaging on human postoperative anterior lens capsule preparations obtained from cataractous lenses during cataract surgery which retained intact monolayers containing viable LECs. Mechanically induced Ca²⁺ waves were recorded, and the contribution of specific signaling pathways was evaluated by pharmacological intervention using apyrase (an ATP-hydrolyzing enzyme) and carbenoxolone (CBX; a gap-junctional blocker). To interpret the experimental results, we developed a biophysically detailed computational model of the LEC monolayer, incorporating intracellular Ca²⁺ dynamics, gap-junctional IP₃/Ca²⁺ diffusion, and extracellular ATP signaling. Results: Apyrase moderately reduced the spatial extent, amplitude, and duration of Ca²⁺ waves without affecting propagation speed. In contrast, CBX significantly suppressed wave transmission, limiting activation to cells directly adjacent to the stimulation site. Simulations reproduced key experimental features and indicated that neither pure gap-junctional nor purely paracrine signaling mechanisms alone could explain the observed dynamics. Instead, a hybrid mechanism combining gap-junctional communication and partially regenerative ATP release was required. Conclusions: Our results highlight the cooperative roles of gap-junctional and ATP-based paracrine signaling in mediating mechanically induced Ca²⁺ wave propagation in the human lens epithelium. This dual-pathway mechanism may be critical for coordinated cellular responses that support physiological processes such as ion homeostasis and transparency maintenance in the human lens.
Keywords: human lens epithelium, calcium signaling, intercellular communication, calcium imaging, computational model
Published in DiRROS: 16.12.2025; Views: 0; Downloads: 0
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Abstract: The current study aims to improve clarithromycin bioavailability and effectiveness in complicated intra-abdominal infection management. Therefore, clarithromycin-loaded submicron dual lipid carriers (CLA-DLCs) were developed via hot high shear homogenization technique and evaluated for colloidal parameters, release behavior, stability study, and in-vitro antibiofilm activity. Bioavailability and therapeutic efficacy of optimized formulation on hampering cytokines storm induction was determined in E. coli-induced peritonitis. The developed CLA-DLCs (particle size 326.19 ± 24.14 nm, zeta potential −31.34 ± 2.81 mV, and entrapment efficiency 85.78 ± 4.01%) exhibited smooth spherical shapes and sustained in vitro release profiles. Long-term stability study of optimized CLA-DLCs ensured maintenance of colloidal parameters for 1 year at room temperature. In vitro antimicrobial studies revealed 3.43-fold higher anti-biofilm activity of CLA-DLCs compared with clarithromycin. In addition, the relative bioavailability of CLA-DLCs was enhanced 5.89-fold compared to pure drug in rats. The remarkable decrease in microbial burden in blood as well as tissues, along with oxidative stress markers (lipid peroxidation, myeloperoxidase activity, and carbonylated protein level) and immunological markers (total leukocyte count, neutrophil migration, NO, TNF-, and IL-6) on treatment with CLA-DLCs enhanced the survival in a rat model of peritonitis compared with the pure drug and untreated groups. In conclusion, CLA-DLCs hold promising potential in management of intra-abdominal infections and prevention of associated complications.
Keywords: clarithromycin, E. coli, peritonitis, submicron dual lipid carriers
Published in DiRROS: 16.12.2025; Views: 1; Downloads: 1
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Abstract: We study the problem of computing the diameter and the mean distance of a continuous graph, i.e., a connected graph where all points along the edges, instead of only the vertices, must be taken into account. It is known that for continuous graphs with $m$ edges these values can be computed in roughly $O(m^2)$ time. In this paper, we use geometric techniques to obtain subquadratic time algorithms to compute the diameter and the mean distance of a continuous graph for two well-established classes of sparse graphs. We show that the diameter and the mean distance of a continuous graph of treewidth at most $k$ can be computed in $O(n \log^{O(k)} n)$ time, where $n$ is the number of vertices in the graph. We also show that computing the diameter and mean distance of a continuous planar graph with $n$ vertices and $F$ faces takes $O(n F \log n)$ time.
Keywords: diameter, mean distance, continuous graphs, treewidth, planar graphs
Published in DiRROS: 16.12.2025; Views: 2; Downloads: 2
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Keywords: živila, prehransko profiliranje, prehranske trditve, zdravstvene trditve, označbe živil, žita za zajtrk
Published in DiRROS: 16.12.2025; Views: 8; Downloads: 6
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