MORPHOLOGICAL ASSESSMENT OF THE LUNGS IN POST-COVID-19 SYNDROME: ANALYSIS OF AUTOPSY MATERIAL.

OBJECTIVE: The aim was to reveal the morphological features of the lungs in post-COVID-19 syndrome. PATIENTS AND METHODS: Materials and methods: The material of the study was autopsy material - fragments of the lung tissue from 96 deceased (59 men and 37 women). During the lifetime, all patients had in anamnesis COVID-19 of varying severity, and after the treatment of this infection, they had various manifestations of respiratory failure until death. The average duration of the post-COVID-19 period was 148.6±9.5 days. Based on the severity of COVID-19 in anamnesis, all cases were divided into three groups. Group 1 included 39 cases with mild COVID-19 in anamnesis. Group 2 included 24 cases with moderate severity of COVID-19 in an-amnesis. Group 3 included 33 cases with severe COVID-19 in anamnesis. Histological, histochemical, morphometric and statistical research methods were used. RESULTS: Results: Morphological features of the lungs in post-COVID-19 syndrome were the presence of pneumosclerosis; focal-diffuse immune cells infiltration; emphysematous and atelectatic changes; degenerative-desquamatic changes in the alveolar epithelium; metaplastic changes of connective tissue; dystrophic calcification; dystrophic, metaplastic and dysplastic changes in the epithelial layer of bronchial tree; hemodynamic disorders. Pneumosclerosis, focal-diffuse immune cells infiltration, alterative changes in the alveolar epithelium, emphysematous and atelectatic changes, hemodynamic disorders increased with an increase the severity of COVID-19. Metaplastic changes of connective tissue, dystrophic calcification, dystrophic, metaplastic and dysplastic changes in epithelial layer of bronchial tree did not depend on the severity of the infection. CONCLUSION: Conclusions: The changes identified by the authors help to explain pulmonary manifestations of post-COVID-19 syndrome. They should be the basis for the oncological alertness formation among doctors, the development of rehabilitation and treatment measures for such category of patients.

Interrelationship of endothelial function parameters in children with bronchial asthma in exacerbation and remission.

INTRODUCTION: In children with asthma, endothelial dysfunction signs are observed, and their extent depends on the severity of the disease. These changes are also present in remission. High level of soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1) expression causes active adhesion of inflammatory cells and can indicate direct endothelium participation in development and supporting of chronic inflammation. Bronchial asthma (BA) is characterised by airways chronic inflammation. A special role in this inflammatory process formation is played by development of endothelial dysfunction. The aim of the study was to evaluate endothelial state in children with clinically stable and exacerbated asthma. MATERIAL AND METHODS: 91 children with persistent asthma were examined. Among them there were 40 patients with mild persistent (group I), 34 subjects with moderate persistent (group II) and 17 individuals with severe persistent (group III) asthma. 20 healthy children were selected as controls. The serum levels of sVCAM-1 were determined by enzyme-linked immunosorbent assay (ELISA). The ultrasound assessment of endothelium-dependent flow-mediated dilation of the brachial artery (FMD%) has been made. Ultrasonography has been used for investigation of the intima-media thickness (I-M) complex. Data analysis was performed with the Statsoft Statistica Version 8 (Tulsa, OK). RESULTS: The serum levels of sVCAM-1 were significantly increased in the patients with asthma exacerbation (p < 0.001) and remission (p < 0.001), compared with the controls. The index of FMD% was significantly diminished in the patients of I, II, III group with exacerbation (p < 0.001) and stayed lower in the subjects with asthma in remission (p < 0.001), compared with the controls. The thickness of I-M complex was significantly increased in the patients of I, II, III group, compared with the controls (p < 0.001). The endothelium parameter levels: sVCAM-1 (H = 56.11, p = 0.0001), FMD% (H = 43.20, p = 0.0000), the thickness of I-M complex (H = 49.37, p = 0.0000) depend on the severity of the disease. Correlations between the endothelium and pulmonary function parameters were proved (p < 0.05). CONCLUSIONS: Endothelial dysfunction in children with asthma was determined. Dependence of severity of the disease on functional state of the vascular endothelium was proved.

Structural Transformations in Austenitic Stainless Steel Induced by Deuterium Implantation: Irradiation at 295 K.

Deuterium thermal desorption spectra were investigated on the samples of austenitic steel 18Cr10NiTi pre-implanted at 295 K with deuterium ions in the dose range from 8 × 10(14) to 2.7 × 10(18) D/cm(2). The kinetics of structural transformation development in the steel layer was traced from deuterium thermodesorption spectra as a function of deuterium concentration. Three characteristic regions with different low rates of deuterium amount desorption as the implantation dose increases were revealed: I-the linear region of low implantation doses (up to 1 × 10(17) D/cm(2)); II-the nonlinear region of medium implantation doses (1 × 10(17) to 8 × 10(17) D/cm(2)); III-the linear region of high implantation doses (8 × 10(17) to 2.7 × 10(18) D/cm(2)). During the process of deuterium ion irradiation, the coefficient of deuterium retention in steel varies in discrete steps. Each of the discrete regions of deuterium retention coefficient variation corresponds to different implanted-matter states formed during deuterium ion implantation. The low-dose region is characterized by formation of deuterium-vacancy complexes and solid-solution phase state of deuterium in the steel. The total concentration of the accumulated deuterium in this region varies between 2.5 and 3 at.%. The medium-dose region is characterized by the radiation-induced action on the steel in the presence of deuterium with the resulting formation of the energy-stable nanosized crystalline structure of steel, having a developed network of intercrystalline boundaries. The basis for this developed network of intercrystalline boundaries is provided by the amorphous state, which manifests itself in the thermodesorption spectra as a widely temperature-scale extended region of deuterium desorption (structure formation with a varying activation energy). The total concentration of the accumulated deuterium in the region of medium implantation doses makes 7 to 8 at.%. The resulting structure shows stability against the action of deuterium ion implantation. This manifests itself in a nearly complete ceasing of deuterium accumulation from a newly implanted dose (radiation-resistant structure).

Structural transformations in austenitic stainless steel induced by deuterium implantation: irradiation at 100 K.

Deuterium thermal desorption spectra were investigated on the samples of austenitic stainless steel 18Cr10NiTi preimplanted at 100 K with deuterium ions in the dose range from 3 × 10(15) to 5 × 10(18) D/cm(2). The kinetics of structural transformation development in the implantation steel layer was traced from deuterium thermodesorption spectra as a function of implanted deuterium concentration. At saturation of austenitic stainless steel 18Cr10NiTi with deuterium by means of ion implantation, structural-phase changes take place, depending on the dose of implanted deuterium. The maximum attainable concentration of deuterium in steel is C = 1 (at.D/at.met. = 1/1). The increase in the implanted dose of deuterium is accompanied by the increase in the retained deuterium content, and as soon as the deuterium concentration attains C ≈ 0.5 the process of shear martensitic structural transformation in steel takes place. It includes the formation of bands, body-centered cubic (bcc) crystal structure, and the ferromagnetic phase. Upon reaching the deuterium concentration C > 0.5, the presence of these molecules causes shear martensitic structural transformations in the steel, which include the formation of characteristic bands, bcc crystal structure, and the ferromagnetic phase. At C ≥ 0.5, two hydride phases are formed in the steel, the decay temperatures of which are 240 and 275 K. The hydride phases are formed in the bcc structure resulting from the martensitic structural transformation in steel.