Kirill Silakov

Tumor-associated macrophages (TAMs), key effectors of the innate immune system, actively participate in extracellular matrix remodeling, angiogenesis, and tumor growth. However, their age-associated quantitative and phenotypic distribution in uterine leiomyoma microenvironment remains insufficiently understood. This study aims to evaluate the density and spatial distribution of CD68⁺ and CD163⁺ macrophage immunophenotypes in uterine leiomyoma stroma across distinct patient age groups. Methods: A total of 318 patients with histologically confirmed uterine leiomyoma were stratified into three chronological age cohorts: Group I (≤30 years, n = 42), Group II (31–45 years, n = 216), and Group III (≥46 years, n = 60). Archival paraffin-embedded tumor tissue sections were analyzed histologically with hematoxylin and eosin, and immunohistochemically using antibodies against CD68 and CD163. Digital morphometric analysis was performed using QuPath software on whole-slide images, evaluating median immunopositive cell densities (cells/mm²) across five standardized regions of interest per case. Results: Histological examination confirmed typical benign leiomyoma morphology, with secondary degenerative alterations (hyalinosis, sclerosis, calcification, and aseptic necrosis) being most pronounced in Group III. Immunohistochemical profiling demonstrated an age-associated increase in macrophage infiltration within the tumor stroma. Median CD68⁺ macrophage density was higher in older cohorts, ranging from 11.4 cells/mm² [IQR: 8.6–13.8] in Group I to 16.7 cells/mm² [IQR: 13.9–19.8] in Group II, and 22.4 cells/mm² [IQR: 18.8–26.2] in Group III (p < 0.001). Concurrently, CD163⁺ macrophage density was likewise higher across older cohorts, measured at 9.8 cells/mm² [IQR: 7.4–12.1] in Group I, 19.4 cells/mm² [IQR: 16.1–22.9] in Group II, and 28.6 cells/mm² [IQR: 23.8–33.4] in Group III (p < 0.001). The observed numerical predominance of CD163⁺ cells over CD68⁺ cells in Group III topographically correlated with areas of secondary tissue remodeling and ischemic injury. Conclusions: This study reveals significant unadjusted differences in separately quantified CD68-positive and CD163-positive cell densities within uterine leiomyoma stroma across distinct patient age groups. Higher CD163⁺ cell densities in older cohorts topographically co-distribute with areas of secondary tissue remodeling and ischemic alteration. Because markers were evaluated on separate sequential sections and multivariable adjustments were unfeasible due to subgroup collinearity, these parameters reflect descriptive, marker-specific stromal variations among real-world clinical cohorts rather than independent causal effects of biological aging.

The development of biocompatible implant materials remains a key priority in modern maxillofacial surgery and dental practice. This study presents an evaluation of tissue responses to subcutaneous implantation of 3D-printed constructs made from polyetheretherketone (PEEK) and polymethylmethacrylate (PMMA). A morphological and immunohistochemical analysis was performed at various time points after implantation, using markers such as CD3, CD20, VEGF, and Collagen I. The findings revealed differences in inflammatory response, angiogenesis, and fibrosis depending on the material composition. The results confirm the high biocompatibility of PEEK and highlight its potential for use in reconstructive surgery. Objective: To assess the immunohistochemical response of local tissues following subcutaneous implantation of PEEK and PMMA-based materials, and to determine their biocompatibility for clinical applications. Materials and methods. Soft tissue samples were obtained from experimental animals after subcutaneous implantation of implants made from four different polymers. Morphological and immunohistochemical analyses were conducted using antibodies to CD3, CD20, VEGF, and Collagen I. Quantitative assessment was performed within standardized microscopic fields. Results. The study revealed differences in the inflammatory response, angiogenesis, and fibrosis depending on the material composition. The findings confirm the high biocompatibility of PEEK and demonstrate its potential for use in reconstructive surgery. Mild inflammatory reaction was observed near all implant types; however, the PEEK group exhibited the most stable tissue response, with CD3+ cell density corresponding to 1—2 scores and stable VEGF levels (2—3 scores) throughout the observation period. In contrast, the PMMA group showed a more pronounced immune response, particularly on day 7, where CD3+ lymphocyte density reached 3 scores, exceeding the PEEK group by 2.8-fold (p<0.05); increased expression of VEGF and Collagen I (up to 3 scores) was also observed, followed by a decrease by day 60. Conclusion. The results demonstrate the high biocompatibility and low immunogenicity of PEEK, supporting its use as a preferred implant material. PMMA-based materials may elicit stronger tissue reactions and warrant further investigation and surface optimization.

Cutaneous melanoma remains one of the most aggressive tumors, yet the role innate immunity plays in its progression remains poorly understood. Effector elements with high regulatory potential, capable of both promoting and inhibiting tumor growth—mast cells (MCs), are of particular interest. This includes quantitatively characterizing the interactions between tryptase-positive mast cells (MCs) with atypical Melanin—A⁺ cells and describing their spatial phenotype, in relation to the stage of cutaneous melanoma. A retrospective analysis was carried out on samples retrieved from 128 patients with cutaneous melanoma (AJCC 8th edition: IA–IIID). Histological analysis, histochemistry (toluidine blue, Giemsa), and diplex /multiplex IHC for tryptase and Melan-A were performed; as well as Fluorescence imaging, 3D reconstructions and quantitative mapping in QuPath v 0.6.0. Proximity was assessed by the nucleus-to-nucleus distance: 20 μm (out of interaction). The relative amount of MCs in the intratumoral zone was lower than in the intact dermis, with a simultaneous increase in their absolute density per mm² in the melanoma microenvironment, maximum in the peritumoral area and most pronounced at stage II. Three types of interactions were identified: (i) juxtaposition without secretion, (ii) degranulation of MCs directed to tumor cells, (iii) melanosecretion of Melanin—A⁺ cells directed towards MCs, followed by phagocytosis of melanocores. An inverse intratumoral connection between the number of MCs and the number of Melanin—A⁺ cells was noted; MCs with elongated forms, extensive contacts and polarized tryptase secretion, including granule localization near/at the nuclei of adjacent cells, were frequently observed. The obtained data indicate stage-region-dependent bidirectional cross-talk between melanin and MCs, forming tissue spatial signals, potentially useful as biomarkers and targets for personalized therapy.

Background: Mast cells, key effectors of the innate immune system, are known to participate in various stages of tumor progression, including inflammation, angiogenesis, and extracellular matrix remodeling. Their role in melanoma, particularly in relation to Breslow thickness, pT stage, and AJCC staging, remains unclear. This study aims to quantitatively and phenotypically assess mast cell infiltration in cutaneous melanoma at different stages of progression, focusing on Tryptase- and Chymase-positive subtypes. Methods: This retrospective multicenter study included 124 patients with cutaneous melanoma (AJCC 8th edition, stages IA–IIIC). Histological sections were stained with hematoxylin and eosin, and mast cells were visualized using toluidine blue and immunohistochemistry with anti-Tryptase and anti-Chymase antibodies. Mast cells were counted manually in intratumoral and peritumoral regions by two independent observers. Quantitative data were analyzed using non-parametric tests and presented as median [Q1–Q3]. Results: Histological examination of 124 melanoma samples confirmed typical features of cutaneous melanoma, with nodular melanoma being the most common subtype (68 cases, 54.8%) and the lower extremities identified as the predominant tumor location (47 cases, 37.9%). Toluidine blue staining verified the presence of mast cells in both intratumoral and peritumoral compartments, with the highest density observed in early-stage melanomas. Immunohistochemical analysis identified both Tryptase+ and Chymase+ mast cells. The intratumoral number of Tryptase+ cells declined from 17 [14–19] per HPF at AJCC stage IA to 6 [5–7] per HPF at stage IIIC, while Chymase+ mast cells decreased from 14 [11–16] per HPF to 2 [1–3] per HPF over the same stages. Peritumoral counts also showed a downward trend, although less pronounced. Overall, the most significant reduction was observed in Chymase+ mast cells, suggesting their potential role as markers of melanoma progression. Conclusions: This study highlights the dynamic changes in mast cell populations in cutaneous melanoma, with a pronounced decrease in Chymase⁺ mast cells as the tumor progresses. Further research is needed to explore the mechanistic role of mast cells and their phenotypic shifts in melanoma progression.

Background: Macrophages are key components of the tumor microenvironment and play a critical role in melanoma progression. However, the dynamics of different macrophage subsets, particularly CD68⁺ and CD163⁺ populations, in relation to tumor thickness and stage remain insufficiently characterized. Objective: This study aimed to quantitatively assess intratumoral and peritumoral CD68⁺ and CD163⁺ macrophages in cutaneous melanoma and to investigate their associations with Breslow thickness, pT stage, and AJCC stage. Methods: We conducted a retrospective cohort study of 126 patients with cutaneous melanoma (AJCC stages IA–IIID). Tumor samples were examined histologically and immunohistochemically for CD68⁺ and CD163⁺ macrophages, and quantitative analysis was performed in intratumoral and peritumoral regions. Results: This study included 126 patients with cutaneous melanoma, ranging in stage from IA to IIID. Histopathological analysis revealed that melanoma tissues were primarily composed of irregular clusters of atypical melanocytic cells infiltrating the dermis and subcutaneous fat. Immunohistochemical staining identified CD68⁺ and CD163⁺ macrophages both within the tumor and in the surrounding stroma. Macrophage infiltration significantly increased with tumor thickness (Breslow) and progression to more advanced stages. Specifically, at Breslow thickness 4.0 mm. CD163⁺ macrophages showed similar trends, with a rise from 15.6 ± 2.8 cells at 4.0 mm in the intratumoral zone. Additionally, macrophage density was higher in tumors with ulceration, and both CD68⁺ and CD163⁺ macrophage numbers increased progressively with tumor stage, particularly in advanced stages. The number of CD68⁺ macrophages at stage IA in the intratumoral zone was 21.6 ± 3.1 cells and increased to 56.4 ± 6.8 cells at stage IIID, while CD163⁺ macrophages rose from 13.8 ± 3.2 cells at stage IA to 36.4 ± 4.6 cells at stage IIID. This suggests that macrophage infiltration, particularly CD163⁺ cells, correlates with melanoma progression. Conclusions: Our findings highlight distinct spatial and phenotypic patterns of macrophage infiltration in melanoma progression. The prominent increase in CD68⁺ and CD163⁺macrophages suggests their important role in tumor-associated immunomodulation. Further studies are warranted to elucidate macrophage polarization states and their prognostic and therapeutic implications in melanoma.

BACKGROUND: Melanoma is a malignant neoplasm that arises from melanocytes, which are melanin-producing cells primarily found in the skin. Although rare, melanoma is highly aggressive. In 2023, 13,270 cases of skin melanoma were identified in Russia. The primary risk factor is excessive exposure to ultraviolet radiation. Immunohistochemical studies using markers such as HMB-45 (Human Melanoma Black-45), Melan-A/MART-1 (Melanoma Antigen Recognized by T Cells 1), and S100 are crucial for diagnosing skin melanoma, improving the accuracy of tumor detection, and optimizing treatment. AIM: This study aimed to assess the prognostic significance of melanocytic markers HMB-45, Melan-A/MART-1, and S100 in skin melanoma, taking into account tumor histological subtypes and stages according to the pTNM classification. METHODS: Skin melanoma samples from patients (n = 117) were assessed using immunohistochemistry with antibodies to HMB-45, Melan-A/MART-1, and S100. The results were interpreted based on the histological subtype of the tumor and the Breslow thickness, which was used to determine the disease stage. RESULTS: The count of atypical melanoma cells, considering the histological subtype of the tumor, showed that the S100 marker had the highest sensitivity (91.2%) compared to Melan-A/MART-1 and HMB-45, especially in desmoplastic melanoma. Moreover, S100 and Melan-A/MART-1 demonstrated stable staining regardless of the degree of invasion, whereas the number of HMB-45-positive atypical melanocytes increased as the tumor progressed according to the pTNM classification. CONCLUSION: Immunohistochemical analysis of various histological subtypes of skin melanoma revealed stable expression of S100, Melan-A/MART-1, and HMB-45 proteins in superficial spreading and nodular tumors. In desmoplastic melanoma, the expression of Melan-A/MART-1 and HMB-45 was absent, whereas S100 expression remained. The proportion of S100- and Melan-A/MART-1-positive atypical cells was independent of the degree of tumor invasion (according to pTNM stages). The percentage of HMB-45-positive atypical melanocytes increased proportionally with the thickness of invasion, supporting its prognostic significance.

Modern understanding of melanoma carcinogenesis and progression highlights the importance of identifying risk factors and prognosis at early stages.Purpose of the study. Analysis of clinical characteristics in patients with skin melanoma.Patients and methods. A retrospective analysis of the medical records of 142 patients with skin melanoma has been carried out. Data on age, gender, tumor localization, disease stage according to the American Joint Committee on Cancer (8th ed., 2017), histological types according to the WHO classification (2022), as well as treatment methods and disease outcomes have been analyzed.Results. Among the studied patients with skin melanoma, women predominated – 78 cases (54.9 %), men – 64 cases (45.1 %). The average age of patients was 63 ± 5.6 years, ranging from 29 to 88 years. Melanoma was most frequently diagnosed at advanced stages: stages IIIA–IIID were detected in 53 patients (37.3 %), stages IIA–IIC – in 40 (28.2 %), and stages 0 and IA–IB – in 16 (11.3 %) and 33 (23.2 %) patients, respectively. The predominant histological types were nodular melanoma (48.6 %) and superficially spreading melanoma (38.7 %). The most common tumor localizations were the skin of the lower extremities (32.3 %) and the back (30.9 %). In 23 patients (16.2 %) with disease progression, metastases were detected in the brain, lymph nodes, liver, lungs, and bones.Conclusions. The carried-out analysis can help clarify the clinical and morphological features of skin melanoma and improve diagnostic and therapeutic approaches.

Ionizing radiation at early stages leads to radiation-induced death of Langerhans islet cells and acinar cells, resulting in the development of acute/subacute pancreatitis. Conducting studies on radiation-induced changes in the pancreas following electron beam irradiation appears to be of great interest, and the evaluation of radioprotective agents for safeguarding normal tissues from radiation is equally important. The aim of this study was to preclinically investigate the antioxidant properties of N-Acetylcysteine in an animal model of radiation-induced pancreatitis over a three-month period. In this study, it was proven for the first time that even electrons can lead to characteristic signs of radiation-induced pancreatitis, the degree of which was assessed based on the levels of insulin, glucose, and amylase. Thus, conducting electron therapy also increases the risks of insulin resistance, as well as X-ray and gamma radiation. For the first time, a comprehensive analysis of biochemical, morphological, and immunohistochemical markers in the pancreas of a large cohort of electron-irradiated animals was conducted, including both acute and delayed effects of electron exposure. The crucial role of interleukins in shaping both the cellular and vascular components of the inflammatory response was identified. Additionally, the radioprotective properties of N-Acetylcysteine during electron irradiation of the pancreas were evaluated for the first time, and its effectiveness in reducing both acute and late complications of electron therapy was demonstrated. Thus, it can be concluded that N-Acetylcysteine is capable of effectively suppressing the inflammatory response in the pancreas.