HISTOULTRASTRUCTURAL FEATURES OF THYMOCYTES DUE TO THE IMPACT OF THE EXPERIMENTAL GENERAL DEHYDRATION OF A MILD DEGREE.

OBJECTIVE: The aim: The objective of the current study was to reveal ultrastructural changes in rats' thymocytes in experimental data in conditions of mild general dehydration. PATIENTS AND METHODS: Materials and methods: The study was conducted on 20 non-linear adult male laboratory rats weighing 150-170 g. Histological and semi-thin slides of the thymus were prepared according to the required guidelines. RESULTS: Results: On average, in the cortical zone of the thymus, there was decreased cellularity by 13.4% (p<0.001), while in the medulla zone this indicator turned out to be unreliable - 5.5% (р=0.19), compared to the indicators in animals of the control group. The study showed that a slight degree of general dehydration of the body causes ultrastructural changes in the thymus and is accompanied by a cell-mediated response of the central link of immunogenesis and results in morphological changes in the thymus, which are atrophic in nature with a typical pattern of remodeling of the organ's microstructure, which corresponds to cellular aging and the associated sign of accelerated involution. CONCLUSION: Conclusions: General dehydration of a mild degree in the experiment is accompanied by a cell-mediated response of the central link of immunogenesis and results in morphological changes in the thymus, which are atrophic in nature with a typical pattern of remodeling of the organ's microstructure, which corresponds to cellular aging and the associated sign of accelerated involution.

Intestinal intussusception in a child with Peutz-Jeghers syndrome: case report.

Peutz-Jeghers syndrome (PJS), an uncommon inherited autosomal dominant disorder, is distinguished by mucocutaneous pigmentations, many gastrointestinal hamartomatous polyps, and a higher incidence of gastrointestinal tract, genitourinary, and extracolonic malignancies. Recurrent acute intestinal obstruction, in particular intussusception in the young, is a serious sequalae of PJS. Case presentation: A clinical observation of a 5-year-old patient with a complicated course of PJS is presented. Emphasis on recurring episodes of acute abdomen, clinical diagnosis including polyp histopathology, and surgical management is emphasised. Clinical findings and investigations: While an inpatient, bloodwork demonstrated severe iron deficiency anaemia (haemoglobin 72 g/l, red blood cell 3.1×1012/l) and multiple melanin pigmentations measuring 2-4 mm in size on the lip mucosa during a physical examination. Erosive duodenopathy and polyposis of the stomach were discovered via fibroesophagogastroduodenoscopy (multiple gastric polyps 5-10 mm in size). Acute intussusception of the intestine was discovered by ultrasonography. Interventions and outcome: A mid-median laparotomy was performed alongside manual disinvagination with gut viability intact. Histopathology of excised polyps revealed smooth muscle hyperplasia and Ki67 protein (MIB-1) positivity with small intestinal hamartomatous polyps seen macroscopically. Conservative management was initiated for standard postoperative care and intestinal motility. Patient was discharged 9 days postoperatively. Relevance and impact: Based on literature data, modern ideas concerning aetiology, diagnosis, and management of patients with PJS are considered. Attention is focused on the high risk of developing cancer of various localisation in PJS, recommendations are given for cancer screening and clinical observation of patients with hereditary gastrointestinal syndromes in childhood.

MORPHOLOGICAL FEATURES OF TUBULAR BONES REPARATIVE REGENERATION UNDER THE INFLUENCE OF ANTITUMOR CHEMOTHERAPEUTICS.

OBJECTIVE: The aim: Determination of morphological features of reparative regeneration of diaphysis defect of long tubular bones under the influence of antitumor chemotherapeutics in a model experiment. PATIENTS AND METHODS: Materials and methods: 96 white nonlinear rats after application of the perforated defect of the femur were administered the appropriate antitumor drug (doxorubicin, 5-fluorouracil, methotrexate) three times with an interval of 21 days. Morphological features of bone tissue formation and remodeling in the regenerate area were studied using histological and morphometric methods. RESULTS: Results: The inhibitory effect of antitumor chemotherapeutics on the formation of regenerate, expressed by slowing down the process of bone tissue differentiation was found. This is confirmed by a decrease in the area of reticulofibrous and lamellar bone tissue, chaotic arrangement and narrowing of bone trabeculae with uneven color, slow formation of bonding lines between the maternal bone and the regenerate. CONCLUSION: Conclusions: The revealed morphological features of reparative regeneration of the diaphysis defect of long tubular bones under the influence of antitumor chemotherapeutics doxorubicin, 5-fluorouracil and methotrexate in a model experiment indicate a slowing of reparative regeneration processes at all stages of recovery after injury.

STRUCTURAL CHANGES OF LONG TUBULAR BONES OF MATURE RATS UNDER THE HYPERGLYCEMIA.

OBJECTIVE: The aim: To evaluate morphological changes in long tubular bones of mature rats under the influence of experimental hyperglycemia. PATIENTS AND METHODS: Materials and methods: The study was conducted on 140 nonlinear white male rats divided into two groups. The experimental group included rats that were introduced into a state of hyperglycemia by a single intraperitoneal injection of an alloxan dihydrate solution at a dose of 150 mg / kg body weight in 0.9% sodium chloride. The control group included rats that were injected with a similar volume of 0.9% sodium chloride one time intraperitoneally. The animals were taken out of the experiment on the 2nd, 30th, 60th, 90th, 120th, 150th and 180th day. Right and left femur and humerus were studied by morphometric and histological methods. RESULTS: Results: Under conditions of prolonged uncontrolled hyperglycemia in mature rats, there is a slowdown in the growth rate of length and thickness of femur and humerus. This is indicated by a significant decrease in the length of bone and its diaphyses, as well as by a decrease in the cross-sectional area of the diaphysis, the width of the proximal and distal epiphyses, starting from 120 and 90 days of the experiment, respectively. The relative area of trabecular tissue, thickness of trabeculae and epiphyseal cartilage decreases in comparison with animals of the control group. The diameter of osteons and their channels increases in cortical tissue. Changes in the microarchitecture of the trabecular and cortical compartments of femur and humerus under conditions of hyperglycemia are similar and are characterized by a reduced bone mass, bone disorder progression and remodeling disorders. CONCLUSION: Conclusions: Prolonged uncontrolled experimental hyperglycemia leads to slow growth of femur and humerus in mature rats, which is accompanied by an increase in microarchitecture disorder of the trabecular and cortical compartments, causing miniaturization of bones and, consequently, violation of their biomechanical properties and increased risk of fractures.