Background: Nicotine-containing vaporized liquids—composed of propylene glycol, glycerin, water, flavorings, and the thickening agent vitamin E acetate—have been implicated in the development of EVALI. Under conditions of low liquid levels and overheating, these substances release toxic carbonyl compounds (e.g., formaldehyde, acetaldehyde, acrolein). In a 2019 national survey, 3.5% of adolescents aged 13–15 reported cigarette use, and 10% used e-cigarettes. Aim: To study the changes in the behavior, lung, and hippocampal structures of rats due to the effects of electronic cigarettes and their vapor. Materials and Methods: In this study, nineteen 14-day-old SHR rats were exposed to 1 g/mg/day of nicotine and dry hit vapor (control, nicotine and dry hit groups) for four weeks. Behavioral assessments (Open Field Test, Elevated Plus Maze, Conditioned Place Preference), bronchoalveolar lavage (BAL), and histological analysis of lung and hippocampal tissue were conducted. Results: The dry hit vapor group showed significantly reduced body weight (p=0.034), increased anxiety (p=0.006, p=0.025), and avoidance of the smoky chamber. BAL revealed elevated total cells, neutrophils, and macrophages (p=0.01, p=0.04) in both nicotine and dry hit groups. Lung tissue exhibited alveolar septal thickening, inflammation, and emphysema- like changes. Extensive neuronal death was observed in the hippocampus. Conclusion Anxiety-like behavior was observed in both the burn and control groups. Analysis of BAL in the dry hit group revealed inflammation predominantly characterized by macrophage infiltration. Histological examination of lung tissue from both experimental groups demonstrated a reduction in the number of alveoli, accompanied by acute inflammation and thickening of the interalveolar septa. In the hippocampal region, neuronal loss and a reduction in neuronal density were also observed.

The study is devoted to the morphological characteristics of the maturation of lung tissue structures in the fetal period. Fetal histology of the lungs presents the intrauterine development of lung tissue in four successive stages: pseudoglandular, canalicular, saccular and alveolar, each has specific morphological criteria. The following morphological features are predetermined: the development of alveolar epithelium, the ratio of mesenchyme towards the area in alveolar spaces, the degree of proliferation and location of vessels of the microcirculatory bed towards prealveolar partitions. During the fetal period the alveolar columnar epithelium is flattened and differentiates into alveolocytes type I lung histology with the demonstration of histological preparations of the lungs at different stages of intrauterine development. Keywords: fetal lungs, prealveolar structures, pseudoglandular stage, canalicular stage, alveolar stage, alveolar capillary membrane, immunohistochemical study. 16 and II, the area of the mesenchyme gradually decreases and by the birth of a full-term newborn kid it is present mainly in the thickness between the alveolar septa, microcirculation vessels, initially laying deep in the thickness of the mesenchymal tissue, gradually proliferate, approach the pre-alveolar epithelium, channeling it with the formation of alveolar capillary membranes. Air exchange in the lung tissue is mainly provided with two factors: the presence of second-order alveolocytes capable of producing surfactant, and a sufficient formation of alveolias well. This work summarizes the basics of fetal lung histology with the demonstration of histological preparations of the lungs at different stages of intrauterine development.

Introduction Gastric ulcer is one of the most common disorders considering the gastrointestinal tract, it affects 5% of the population around the world, so its prevention and management are considered very important challenges. Researchers have revealed several causes of gastric ulcer; these include an imbalance between aggressive and intrinsic defensive factors. Gastric ulcer is a very common gastrointestinal disease that may lead to dangerous complications and even death. The aggressive factors include non-steroidal anti- inflammatory drugs(NSAID),alcohol, psychological stress and Helicobacter pylori infection, cytoprotective intrinsic factors include mucosal blood flow, bicarbonate, mucus, cell renewal, growth factors, NO and prostaglandins, NSAID-induced gastric damage is known to be the most common and dangerous side-effect of these drugs and accounts for 25% of gastric ulcer cases.
Indomethacin (INDO) is considered to be the most common NSAID known to induce experimental gastric ulcer and has been documented to have a higher potential to cause gastric injury than other commonly used NSAIDs.
Most of the drugs which are used for wound healing are imported in Mongolia. It is required to develop drug formulation and increase local productions used for the treatment of wound healing. For the purpose of solving the above problems, we aimed to prepare new drug formulation from Cacalia hastata L. for the treatment. of wound healing. Cacalia hastata L. is a medicinal plant, member of the family Asteraceae. Cacalia hastata L. is widely used for the Mongolian traditional medicine to treat wound healing, gastric ulcer, poisoning fever, liver fever, bile fever, oral cavity, and gynecological diseases