Vol 163, No 4 (2025)

BACKGROUND: The quantitative and morphofunctional characteristics of mast cells can serve as an indicator of tissue reactivity in response to radiation exposure, as well as a criterion for compensatory-adaptive processes after irradiation and the use of radioprotectors.

AIM: The work aimed to present the morphofunctional and quantitative characteristics of splenic mast cells of laboratory mice following fractionated total X-ray irradiation and oral administration of beta-D-glucan.

METHODS: An experimental, single-center, prospective, controlled study was conducted. Spleen samples from laboratory mice (n = 23) were assessed. The population of mast cells was quantitatively assessed on histological sections of the spleen. The mice were divided into 5 groups: Group 1 included intact animals (n = 3); Group 2 included irradiated animals with a total absorbed dose of 7 Gy (n = 5); Group 3 included irradiated animals with a total absorbed dose of 7 Gy who received oral soluble beta-D-glucan 15 minutes before irradiation (n = 5); Group 4 included irradiated animals with a total absorbed dose of 18 Gy (n = 5); Group 5 included irradiated animals with a total absorbed dose of 18 Gy who received oral soluble beta-D-glucan 15 minutes before irradiation (n = 5). Samples were collected on days 14 and 30 after the start of experimental exposure. Samples were fixed in 10% buffered formalin, dehydrated in alcohol, and embedded in paraffin. The Romanowsky–Giemsa staining was used. The structure and number of mast cells were assessed on each histological slide. Statistical analysis of the findings was performed.

RESULTS: The density of mast cells in the spleen of laboratory mice at an absorbed dose of 7 Gy changed insignificantly compared to the intact group. At a total absorbed dose of 18 Gy, there was a significant increase in the density and functional activity of mast cells. Beta-D-glucan administration before irradiation at a total absorbed dose of 7 Gy and 18 Gy reduced the number of mast cells by 2.5 times and 1.25 times, respectively, compared to irradiated animals without beta-D-glucan administration (Group 4).

CONCLUSION: The density of mast cells in the spleen depends on the absorbed dose of X-ray irradiation. Beta-D-glucan administration 15 minutes before exposure reduces the density of mast cells, which can be considered a positive radioprotective effect.

BACKGROUND: The morphology of intramural autonomic nerve ganglia of the myenteric (MP) and submucosal (SP) plexuses of the intestine in adult animals has been studied in sufficient detail, whereas data on age-related features of these structures remain limited.

AIM: This study aimed to investigate the morphometric characteristics of intramural autonomic nerve ganglia of the myenteric and submucosal plexuses of the small and large intestines in rats during postnatal ontogenesis.

METHODS: The study used male Wistar rats of different age groups: newborns; 10, 20, 30, and 60 days after birth; and 12 and 24 months of age. Immunohistochemical analysis was performed using fluorescently labeled antibodies to protein gene product 9.5 (PGP9.5).

RESULTS: During postnatal ontogenesis, the number of ganglia per 1 mm² decreases, whereas the ganglion area increases in both the small and large intestines. The mean area of nerve ganglia in the MP of the small and large intestines increases from birth up to day 60, whereas in the SP, this increase occurs during the first 30 days of life. The mean density of ganglia per 1 mm² in the MP decreases during the first 60 days in the small intestine and during 12 months in the large intestine. In the SP, this parameter decreased in both the small and large intestines during the first 60 days of life. The mean number of PGP9.5-immunoreactive neurons per ganglion in the MP remains unchanged during postnatal ontogenesis, whereas in the SP, it increases during the first 10 days after birth.

CONCLUSION: In postnatal ontogenesis, during the first 30 days of life, the size of ganglia in the MP and SP increases, whereas their density per unit surface of the small and large intestines decreases. The shape of ganglia and the number of neurons in the MP ganglia do not change during postnatal ontogenesis. In contrast to the MP of the small and large intestines in rats, the SP ganglia remain immature at birth, with the formation of the SP ganglion network during the first 10 days after birth.

BACKGROUND: Regeneration of the distal phalanx in adult mammals is a rare example of complete tissue restoration without fibrosis. Spiny mice of the genus Acomys are capable of regenerating multiple tissues, including epidermis and muscle, without scar formation. However, the ability of Acomys cahirinus to fully regenerate the distal phalanx remains unknown.

AIM: The work aimed to assess distal phalanx regeneration after amputation in spiny mice.

METHODS: Distal phalanx regeneration in Mus musculus and A. cahirinus was evaluated over 28 days after amputation. The distal phalanx was amputated distal to the nail bed to model epimorphic regeneration via blastema formation. Amputation proximal to the nail bed was performed to model injury leading to fibrotic scar formation. Recovery was assessed visually, by micro-computed tomography, and histologically.

RESULTS: Unlike M. musculus, which showed complete restoration of all tissue components after distal phalanx amputation, A. cahirinus failed to achieve full regeneration. Following amputations distal to the nail bed, A. cahirinus exhibited digital shortening and clubbing. Histological analysis demonstrated an increase in bone tissue volume within the damaged phalanx in spiny mice. Micro-computed tomography revealed that the bone damaged by amputation underwent lysis up to complete degradation, with bone hypertrophy in the next phalanx of the injured digit, located proximal to the amputation plane.

CONCLUSION: A. cahirinus does not exhibit complete digit regeneration after distal phalanx amputation. This outcome could be attributed to excessive lysis of the damaged bone and insufficient blastema formation at the site of injury.

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.

Tissue microarrays (TMAs) are a promising method for high-throughput analysis of archived tissue samples. Laboratories using conventional manual methods for creating TMAs face the challenge of increasing efficiency and standardization, which is particularly crucial for oncomorphological research and diagnostics. This can be achieved through the automation of the process.

This review focuses on the capabilities and advantages of automated systems for TMA creation over manual methods, with an emphasis on their application in the analysis of Ewing sarcoma and other undifferentiated round cell sarcomas. In the analyzed works, automated systems were used to extract and position tissue cores into recipient paraffin blocks, followed by histological and immunohistochemical analyses on the obtained TMA sections. Furthermore, the quality of the tissue microarray sections was evaluated. In these works, automated systems demonstrated high precision in positioning tissue cores, significantly accelerating TMA creation and improving the quality of the resulting sections.

Thus, automated systems for TMA creation offer significant advantages over manual methods, ensuring standardization and increasing the productivity of laboratory research. Automated systems allow for the efficient analysis of large sample sets, which is especially important for the validation of diagnostic and prognostic biomarkers. The published works highlight the need for further development and wider implementation of automated systems in oncomorphological research to enhance their efficiency and reproducibility.

On August 26, 2025, Professor Aleksandr A. Stadnikov, a prominent Soviet and Russian histologist, celebrated his 80th birthday. His entire career has been connected with the Orenburg Medical University (formerly Institute—Academy—University), where he rose through all stages of the academic hierarchy, from assistant (since 1971), to associate professor (since 1983), and later Head of the Department of Histology (1988–2025). In parallel, between 1993 and 2009, Professor Stadnikov served as vice-rector, and in 2009 as acting rector of the Orenburg Medical Academy. Since 2025, he has continued his work as a professor at the Department of Histology. His research interests include comparative and evolutionary histology, embryonic and postnatal morphogenesis, neuroendocrine regulation of morphogenesis and regeneration, and the history of histology. His research into the interactions between prokaryotic and eukaryotic cells has made a significant contribution to cell biology. Professor Stadnikov established a new direction within the Orenburg school of histology, focusing on neuroendocrine regulation of cells, tissues, and organs. His pioneering studies clarified the role of neuroendocrine regulation in the interactions between prokaryotes and eukaryotes. For more than 50 years, Professor Stadnikov has taught at Orenburg Medical University while conducting extensive research. He has earned the respect and admiration of generations of students, teachers, and physicians. Professor Stadnikov is an example of a gifted scientist and educator who motivates and empowers others. For his students and colleagues, he remains a figure of high scientific and moral authority.

This article commemorates the 110th anniversary of the birth of Professor Iraida M. Pestova, Doctor of Sciences in Biology, a prominent Soviet-era histologist. Pestova graduated from the Sverdlovsk State Medical Institute (now Ural State Medical University) as part of its legendary first cohort. After completing her studies in 1936, she entered the postgraduate program in the Department of Normal Anatomy, where she worked for a year under Professor Alexei P. Lavrentiev, the founder and first head of the department. In 1937, Pestova moved to Perm and continued her postgraduate studies in the Department of Histology of the Perm State Medical Institute under Professor Petr Ya. Lakhovsky. From this point began her remarkable career as a histologist, marked by significant scientific achievements and long-standing leadership of the Department of Histology at the Perm State Medical Institute. At the time, the department’s primary research focus was the evolution of the immune and hematopoietic systems of vertebrates. As a scholar, Pestova followed in the tradition of Alexei A. Zavarzin, an eminent Soviet histologist, academician of both the Academy of Sciences and the Academy of Medical Sciences of the USSR, and founder of evolutionary histology. It was in Perm that Zavarzin established the scientific foundations of evolutionary histology, which were further developed by Evgenii S. Danini, Pestova’s mentor. The article highlights the key stages of Professor Pestova’s life and career, her contribution to science and teaching, as well as her professional and personal qualities.