ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 The images are compared to both formalin-fixed paraffin-embed- ded and frozen sections of the same organ and the speed of the measurement is evaluated. Conclusion: Our self-built multiphoton microscope can create H&E images of fresh bulk tissue without freezing or sectioning. A quick staining protocol has been developed to achieve a competitive imaging speed. The technique offers a fast alternative to the frozen section workflow avoiding delays by transporting the tissue to the pathology lab. We will start a clinical study on basal-cell carcinoma to evaluate the diagnostic accuracy and try analysing our digital image data by modern AI algorithms in the future. E-PS-19-002 Three-dimensional observations of metastatic cancer cells in body fluids using label-free optical diffraction tomography U. Jo*, J. Jeong, T. Kim, T. Kim, M. Kim, S.J. Jang, J.S. Song, C. Pack *Department of Pathology/Asan Medical Center, Republic of Korea Background & objectives: Label-free optical diffraction tomogra- phy (ODT) can overcome the limitation off conventional cell imaging technologies. Rapid diagnosis of metastatic carcinoma in body fluids is necessary for deciding a stage. We evaluated the metastatic cancer cells using ODT as a diagnostic tool. Methods: Two kinds of primary cultured cells of pulmonary adenocarcinoma and gastric adenocarcinoma were used as control group and ten body fluid samples containing metastatic carcinomas, such as pleural fluid and ascites were used as experimental group. Reconstruction of a three-dimensional (3D) refractive index (RI) map using ODT. Tumour volume and three dimensional morphology were observed through 3D optical method. Results: All cancer cells presented prominent nucleoli, less cytoplasm, and mostly uniformed nucleus. The average volume of the gastric adenocarcinoma cells and pulmonary adenocarcinoma cells was 5169.3um3 and 3939.3um3, respectively. The surface of the cells was varied and it was generally uneven accompanying process or blebs rather than smooth. Conclusion: There is no study comparing cancer cell cyto-mor- phology using ODT so far. Since there is no staining process after obtaining the body fluid, rapid identification and confirmation of metastatic cancer cells may be possible through body fluids from the patients’ bed side. E-PS-19-003 Modifying bioeffects of posturan incorporation Z. Vorontsova, S. Selyavin, E. Kudaeva, A. Filin* *Voronezh State Medical University, Russia Background & objectives: The long-term bioeffects of depleted ura- nium after incorporation are of considerable interest from the stand- point of its endogenous effects and in order to identify the reactivity of target organs. Methods: Fragments of biopsy material of the parotid gland and jejunum from 135 mature male rats were used. Reactions to dehy- drogenases were carried out on cryostatic sections of the parotid gland. Intraepithelial lymphocytes and mucosal barrier were detected on paraffin sections of the jejunum stained with hema- toxylin and alcyan blue. Results: Three and six months after a single incorporation of depleted uranium in the parotid gland, a prolonged bioeffect of changes in the light-optical density of dehydrogenases was noted. In acinuses, the indicators were significantly higher than the con- trol ones. There were no differences from the control in the striated excretory ducts. However, there was a significant increase in their extent, stating atypical regeneration and an increase in the viscos- ity of the secretion. Destructive changes of acinuses are noted. The dynamism and depth of penetration of lymphocytes into the jejunum epithelium determined the specificity of the microenvi- ronment for antigen recognition and correlated with severity of the barrier properties of mucin gel. Conclusion: The results of the study have identified a pathoge- netically significant role in the realization of depleted uranium bioeffects. Persistent changes in the parotid gland were a reflec- tion of a violation of the formation and excretion of secretions, suggesting a change in the microflora in the oral cavity, and an increase in the density of the mucosal barrier in the jejunum. The multidirectional nature of the changes revealed a prolonged pattern of reactions characterizing the cumulative radiotoxic bioeffect of depleted uranium. E-PS-19-004 Conceptions of learning factors in undergraduate medical stu- dents. Teaching directed by threshold concepts M.J. Gálvez Medina*, F. Leiva-Cepas, I. Cantarero Carmona, A. Sanz Zorrilla, R. Ortega Salas *Servicio de Anatomía Patológica. Hospital Universitario Reina Sofía, Spain Background & objectives: Students’ cognitive perceptions (SCP) are considered important variables for high-quality learning. In this study, SCP were used to identify histopathological threshold concepts (TC) in medical curricula. The objective is to analyse the perception of medical students’ about TC in Pathology. Methods: A questionnaire was developed and validated to char- acterize SCP of CT in pathology. A sample of 180 medical stu- dents’ participated in the study. Different items were evaluated by means of a Likert-type scale (1-5) on their consideration of each CT in pathology. Statistical analysis was performed (Student’s t test) comparing the values by gender and the differences between different sections. Results: The result of questionnaires related to morphostructural TCs was very distributed in the interval from 1 to 5, being the mean value 3.2/5. CT related to two-dimensional microscopic identifica- tion were scored 4.2/5. Additionally, students identified CT related to the general histogenesis of neoplasms as critical to understand- ing and learning in pathology. Conclusion: The identification of threshold concepts through stu- dents’ perceptions is potentially useful to improve the teaching and learning process in health sciences curricula. The differences observed must be taken into account in the organization in the teaching programming of the Pathology subject and in the entire Medicine degree, to guarantee an autonomous learning process based on specific competencies. E-PS-19-006 Pathological anatomy as an innovative teaching experience in biology students F. Leiva-Cepas*, M.J. Gálvez Medina, A. Sanz Zorrilla, J. Osuna Soto, R. Ortega Salas *University Hospital "Reina Sofía", Spain Background & objectives: Histological image analysis plays a role in studying pathological alterations in diseases, especially in practical S321