MORPHOLOGICAL AND FUNCTIONAL FEATURES OF THE MUCOUS MEMBRANE OF SMALL AND LARGE INTESTINE IN PATIENTS WITH COVID-19 AND IN POST-COVID-19 PERIOD.

OBJECTIVE: The aim: To reveal the morphological and functional features of the mucous membrane of small and large intestine in patients with COVID-19 and in post-COVID-19 period. PATIENTS AND METHODS: Materials and methods: In the present study, the authors used biopsy and autopsy material represented by the fragments of the mucous membrane of small and large intestine. All studied material was divided into 10 groups. Group 1 (comparison group) included autopsy material from the deceased who did not have COVID-19 during their lifetime. Groups 2-4 included autopsy material from the deceased who had COVID-19 of varying severity during their lifetime. Groups 5-7 included biopsy material from patients who had recovered from COVID-19 of varying severity, while the duration of the post-COVID period ranged from 1 to 50 days. Groups 8-10 included biopsy material from patients who had in anamnesis COVID-19 of varying severity (the duration of the post-COVID period lasted from 51 to 100 days). Histological, immunohistochemical, morphometric and statistical research methods were used. RESULTS: Results: The comparative analysis showed a more expressed deficiency of ACE2 in the mucous membrane of small and large intestine in patients with moderate and severe COVID-19 compared with patients in post-COVID-19 period of different duration. In patients who had moderate and severe COVID-19 in anamnesis, ACE2 deficiency decreases with increasing duration of post-COVID-19 period. In patients recovered from mild COVID-19, the ACE2 content increases with the duration of post-COVID-19 period from 1 to 50 days and corresponds to the norm with the duration of this period from 51 to 100 days. CONCLUSION: Conclusions: The comprehensive morphological study conducted by the authors made it possible, firstly, to clarify the morphological and functional features of the mucous membrane of small and large intestine in patients with COVID-19 of various degrees of severity; secondly, to obtain new data about the morpho-functional state of the mucous membrane of small and large intestine in patients, taking into account different duration of the post-COVID-19 period and the severity of the infection.

SEBORRHEIC KERATOSIS: CURRENT STATE OF THE PROBLEM.

OBJECTIVE: The aim is to identify age, gender, clinical and morphological features of seborrheic keratosis. PATIENTS AND METHODS: Material and methods: The study used biopsy material from 196 patients with a clinical diagnosis of "Seborrheic keratosis". In all cases, when studying directions for pathohistological examination, the authors analyzed gender and age characteristics, as well as localization of seborrheic keratosis. The resulting material was fixed in a 10% solution of neutral formalin (ph 7.4) for 24-48 hours. The procedure was carried out according to the generally accepted technique and the material was embedded in paraffin. Sections of 4-5×10-6m thick were made from paraffin blocks for staining with hematoxylin and eosin. The microspecimens were examined using an Olympus BX-41 microscope (Japan). RESULTS: Results: The study revealed a modern feature of seborrheic keratosis -"rejuvenation" of this tumor, as evidenced by its predominant development in patients aged 31 to 50 years. Seborrheic keratosis is more common in men, and is localized mainly on the skin of the face, scalp, neck and back. When diagnosing seborrheic keratosis, the author notes a significant discrepancy between clinical and morphological diagnoses, which actualizes the problem of improving the available clinical research methods and emphasizes the importance of morphological research. Hyperkeratotic and acanthotic histological variants of seborrheic keratosis are the most common. The case of seborrheic keratosis with malignancy and transformation into squamous cell carcinoma, identified by the author, should develop oncological alertness in doctors and patients. CONCLUSION: Conclusions: The study revealed age, gender, clinical and morphological features of seborrheic keratosis, which will contribute to a better understanding of this pathology by the doctors of various specialties, and improve the treatment and diagnostic process.