Vol 49, No 6 (2021)

Rationale: Most data on the effectiveness of systems for the analysis of digital X-ray images have been provided by their developers and require a  high-quality validation in databases prepared independently of the developer.

Aim: To analyze the information content of automatic identification of spherical lung masses with digital X-ray imaging using one of the widely available diagnostic algorithms on publicly unaccessible reference datasets.

Materials and methods: The study was based on the recognition and analysis of digital X-ray images from two publicly inaccessible reference datasets that have the state registration (Russian Federation) with one of the publicly available diagnostic algorithms (FutureMed Analyzer). The study was performed using two models of X-ray screening as examples: Model  1 consisted of 100  X-ray images of the lungs with a  normal: abnormal ratio of 94%: 6%; Model  2 consisted of 5150 chest X-ray images with a normal: abnormal ratio of 97%: 3%.

Results: According to the results of the analysis of the X-ray images with the diagnostic system, 98%  of the images were correctly interpreted with Model 1 and 95% of the images, with Model 2. 83% of the cases from Model  1 and 69% from Model  2% were interpreted as images with lung abnormalities. The percentage of correct answers for differentiation of the chest X-ray images into two categories (normal vs. abnormal) for Model 1 and Model  2 was 95% and 98%, respectively. The sensitivity for detection of abnormal masses ranged from 69% to 83%. The specificity was 99% for the Model 1 chest X-ray images and 96% for the Model  2 chest X-ray images. The underdiagnosis rate was quite low ranging for Model 1 – 17%, and for Model 2  – 31%. The area under the curve for Model 1 was 0.91 and for Model 2 0.85.

Conclusion: The diagnostic efficiency of the automatic image analysis based on the convolutional neuronal networks approaches that of the radiologists. This system of automatic identification of abnormalities was unable to solve the most complex problems of detecting low density spherical masses (like "ground glass" area on computed tomography) and that of shadow summation for abnormalities located in such difficult to interpret zones as lung apices, clavicles, ribs, etc. To select a  suitable system, medical institutions need to conduct preliminary testing in their own models equivalent to the studies performed in a  given institution (parameters for radiography, nature and frequency of abnormalities).

Rationale: 3D modeling of various anatomical structures has recently become a separate area of topographical, anatomical, and biomechanical studies. Current in vivo visualization methods and quantitative analysis in silico allow to perform the precise modeling of these processes aimed at investigation into the pathophysiology of cardiovascular disorders, risk prediction, planning of surgical interventions and virtual refinement of their separate stages.

Aim: To develop tools for elaboration, analysis and validation of personalized models of various structures of the heart and aortal arch taking into account their morphological characteristics.

Materials and methods: We used the results of 14 computed tomography studies from randomized patients without any disease or anomaly of the heart, aortic valve and aortal bulb. The analysis and subsequent transformation of the images were done with Vidar DICOM Viewer, SolidWorks 2016, VMTKLab software. For the FSI modeling of the aortic arch based on the results of functional multiaxial computed (MAC) coronarography (a female patient of 55 years) we developed a personalized model of the ascending aorta and aortic arch at the beginning of the systole. Using HyperMesh software (Altair Engineering Inc., USA) we have built a network of finite element of the luminal area, adventitia, and aortic media. To model mechanical properties of the aortic structures we used an anisotropic hyperelastic material model by Holzapfel – Gasser – Ogden. Material modeling, choice of the limiting antecedents, and analysis of fluid-structure interaction were performed with Abaqus CAE 6.14 software (Simulia, Johnston, USA). Adaptive image meshing by Young was used to elaborate the finite element template of the left ventricle. The algorithm was realized within the IDE PyCharm software media in Python 3.7. The algorithm was realized based on the open-source libraries OpenCV, NumPy, Matplotlib, and SciPy.

Results: The first stage of the development of the aortic valve model included the design of its virtual 3D template. Thereafter, a cohesive geometric model was elaborated. Subsequent stage of the work included the transformation of the aortic valve geometric model into the parametric one. This was done through the use of the “Equations” tool within the SolidWorks. No problems with geometry of the model during its deformation were identified. Aortic segment modeling was based on the data obtained by functional MAC coronarography. Based on this and on Inobitec Dicom Viewer software, we generated a multiplane reconstruction of the zone of interest including anatomical structure of the heart and aortic valve. With the resulting set of contours, we created a 3D model, which then was converted into a polygonal stereolithographic model. We developed an algorithm for adaptive meshing to elaborate a polygonal template capable of deformation that can be used for registration both with the net methods (B-Spline) and based on the image characteristics (homologous pixels).

Conclusion: The resulting parametric 3D model of the aortic valve anatomical structures is capable of adequate transformation of its geometry under external factors. It can be used in simulators of endovascular cardiosurgical procedures.

Rationale: Chemotherapy is one of the lung cancer treatment methods. The search for new substances with antitumor effect against malignant lung neoplasms is relevant because of low efficacy and side effects of cytotoxic agents. A promising substance class with various biological activities, including antitumor, includes alkaloids of the tropolone family, such as heptamerous non-benzoid aromatic compounds. 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)- 5,6,7-trichloro-1,3-tropolone has been synthesized in Institute of Physical and Organic Chemistry; it is a  new compound belonging to 2-quinoline-2-yl derivatives of 1,3-tropolone.

Aim: To assess the antitumor effect of 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)- 5,6,7-trichloro-1,3-tropolone on subcutaneous xenografts of A-549 lung tumor cells in immunodeficient Balb/c Nude mice.

Materials and methods: The study included 50  immunodeficient Balb/c Nude mice divided into 4  experimental groups depending on the dosage of the study substance (0.0055, 0.055, 0.55, and 2.75  mg/g); group 5  was the control group. A-549  cells of lung cancer were used as a xenograft. The antitumor effect of tropolone was evaluated by the inhibition of tumor growth and the index of tumor growth. The experiment lasted for 36 days starting from the first administration of the substances.

Results: The mean tumor volumes on day 36  of the experiment in the control group and four experimental groups were 2729.5; 2150.8; 1746.4; 952.3  and 678.9  mm³ , respectively. The indices of tumor growth in groups  1, 2, 3 and 4 were significantly lower than in group 5 (control) starting from days 24, 21, 21 and 15, respectively, and till the end of the experiment. Maximal differences between groups 4 and 5 were observed at days 33 and 36 (by  3.7, p=0.01 and 4.1, p=0.003  times, respectively).

Discussion: The anti-tumor effect of 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)- 5,6,7-trichloro-1,3-tropolone demonstrated in the study could be related to various mechanisms. For example, numerous studies have shown that its related compound hinokitiol exerts a cytotoxic effect associated with cessation of the cell cycle, apoptosis induction, DNA damage, and autophagic death of tumor cells.

Conclusion: The study demonstrated significant differences in xenograft volumes in all experimental groups, compared to the control group. In mice, 2.75  mg/g bodyweight was the most effective dosage of the studied compound leading to a slow decrease in tumor growth rates and a  decrease in the volumes of subcutaneous xenografts.

Rationale: The study of the structural particulars and functional state of immune cells and primarily lymphocytes is of great importance for both fundamental and clinical medicine. It requires the development of simple and reliable analytic methods that would allow for fast and effective real-time assessment of cell activity.

Aim: To evaluate the effectiveness of the interference microscopy compared to DNA spectrometry, DNA cytometry, and flow cytometry with an internalized fluorescent label CFSE (carboxyfluorescein succinimidyl ester) in the assessment of PHA-induced proliferation of human blood lymphocytes.

Materials and methods: Phytohemagglutinin (PHA)-induced proliferative activity of blood lymphocytes from 10  healthy volunteers was studied with various methodological strategies. Blast transformation of lymphocytes was induced by their incubation for 5 days with PHA 5 μg/mL. The cell proliferative activity was assessed as follows: 1) by DNA spectrometry at 260/280 nm using Tecan Infinite 200  Pro with a  specialized NanoQuant Plate™; 2)  by cytophotometry followed by cell distribution analysis assessing deoxyribonucleic acid (DNA) content after staining with Felgen's dye with an imaging system based on an Olympus BX41 light microscope with a ProgRes CF camera; 3) by flow cytometry using an internalized fluorescent label CFSE; the analysis was performed with a BD FACS Calibur flow cytometer; 4) by measurement of the lymphocyte interference profile with a  modulation interference microscope MIM-340 (Schwabe, Russia). The functional activity of the nucleus (FAN) was determined and used as a criterion for assessment of the lymphocyte functional state.

Results: Incubation of lymphocytes with PHA led to an increase in the linear size by 22.2±2.8%, a  decrease in phase height by 46.3±4.7% (p=0.019), and an increase in FAN by 75.9±9.4%, vs control (p=0.046). As measured by isolated DNA spectroscopy, PHA stimulation of lymphocytes was associated with an increase in the amount of DNA by  55% vs baseline (409.8±22.3  ng/μL and 264.3±25.0  ng/μL, respectively, p=0.049). Felgen's reaction revealed that the proportion of nuclei containing more than 2n DNA was 2% in the control cells and 14.8% in the PHA-activated lymphocytes, with a  difference between the groups of 12.8%. CFSE staining with subsequent incubation and assessment by flow cytofluorimetry demonstrated an increase in the percentage of proliferating cells from 1.68±0.9% in the control to 55.56±5.6% (p=0.00068) in the mitogen-stimulated sample.

Conclusion: Modulation interference microscopy does not require the sample preparation and demonstrated comparable and even higher effectiveness compared to conventional methods for assessment of lymphocyte activity. At the same time, it allows for evaluation of the lymphocyte functional state in real time in the process of cultivation. This opens ample opportunities for evaluation immune cells for research and diagnostic purposes.

Background: Mechanical properties of cell membranes and their structural organization are considered among the most important biological parameters affecting the functional state of the cell. Under the influence of various pathogenic factors, erythrocyte membranes lose their elasticity. The resulting changes in their biomechanical characteristics is an important, but poorly studied topic. It is of interest to study the deformation of native erythrocytes to a depth compatible with their deformation in the bloodstream.

Aim: To investigate the patterns of deep deformation and the particulars of structural organization of native erythrocyte membranes before and after their exposure to physicochemical agents in vitro.

Materials and methods: Cell morphology, nanostructure characteristics, and membrane deformation of native erythrocytes in a  solution of hemoconservative CPD/SAGM were studied with atomic force microscope NTEGRA Prima. Hemin, zinc ions (Zn²⁺), and ultraviolet (UV) radiation were used as modifiers. To characterize the membrane stiffness, we measured the force curves F(h), hHz (the depth to which the probe immersion is described by interaction with a homogeneous medium), and the Young's modulus values of the erythrocyte membrane.

Results: Exposure to hemin, Zn²⁺ and UV radiation led to transformation of the cell shape, appearance of topological defects and changes in mechanical characteristics of erythrocyte membranes. Under exposure to hemin, Young's modulus increased from 10±4  kPa to 27.2±8.6  kPa (p<0.001), exposure to Zn²⁺, to 21.4±8.7  kPa (p=0.002), and UV, to 18.8±5.6  kPa (p=0.001). The hHz value was 815±210  nm for the control image and decreased under exposure to hemin to 420±80 nm (p<0.001), Zn²⁺, to 370±90 nm (p<0.001), and UV, to 614±120 nm (p=0.001).

Conclusion: The results obtained contribute to a  deeper understanding of interaction between membrane surfaces of native erythrocytes and small vessel walls. They can be useful in clinical medicine as additional characteristics for assessment of the quality of packed red blood cells, as well as serve as a basis for biophysical studies into the mechanisms of action of oxidative processes of various origins.

Stroke is the leading cause of adult disability worldwide. The consequences of a stroke can include various disorders, namely, motor, cognitive, emotional, and behavioral disorders, which, in their turn, lead to a decreased daily life activities and self-care ability, and affect quality of life of the patients. This article describes a  clinical case of the implementation of a  new comprehensive program for neurorehabilitation treatment in a female patient in the early recovery period from ischemic stroke with spastic hemiparesis, moderate cognitive impairment and affective disorders. The neurorehabilitation program is based on the use support reaction biofeedback through auditory and visual channels. Classical static and dynamic stabilometric trainings were sequentially used in the patient standing on the platform, as well as exercises with a force joystick for the upper limb in the sitting position. The multifaceted program also included classes with a speech therapist/neuropsychologist, as well as physical therapy with an instructor. The treatment resulted in an improvement in the patient's general condition, restoration of the upper limb movement function, normalization of cognitive functions, and regression of affective disorders. The treatment-related effects were persistent, and the assessment of the neurological status at 3 months' follow-up showed no deterioration of neurological symptoms. Thus, the multifaceted rehabilitation treatment based on the combination of increased physical activity and sensory stimulation, as well as cognitive tasks, may facilitate good recovery after a stroke.