Impact of an E-Learning Histology Course on the Satisfaction and Performance of Medical, Nursing and Midwifery Students / Impacto de un Curso E-Learning de Histología en la Satisfacción y Desempeño de Estudiantes de Medicina, Enfermería y Obstetricia

SUMMARY: The importance and relevance of e-learning courses in medicine and health sciences has increased significantly in the last decade. Despite this, there are few published teaching experiences of e-learning histology courses in the literature worldwide. The histology course we designed was structured on the Moodle platform as a learning management system, and the content was proposed in a synchronous (zoom) and asynchronous (recordings) format. We also included the use of free virtual microscopy tools. This study aimed to investigate the impact of an e-learning histology course on the satisfaction and performance of medical, nursing and midwifery students. The sample included 424 Chilean medical, nursing, and midwifery students from two cohorts. A Likert-type survey was administered at the end of the course. We performed exploratory analysis and ordinary least squares regression. In this study, we present a positive experience of an e-learning histology course. Exploratory factor analysis revealed three main factors related to "e- learning satisfaction", "in-person class activities", and "course design and teaching quality". We also found that there was a positive and significant relationship between students' perceptions of the adaptation of the traditional (face-to-face) histology course into an e-learning format and their academic performance. Our study shows that e-learning histology courses that integrate lectures and practical sessions can be a valuable teaching method for learning histology. Curriculum developers and teachers need to consider the limitations and advantages of this type of teaching and incorporate these three factors into the design and assessment of e-learning histology courses.

La importancia y relevancia de los cursos e-learning en medicina y ciencias de la salud ha aumentado significativamente en la última década. A pesar de ello, existen pocas experiencias docentes publicadas de cursos de histología e-learning en la literatura a nivel mundial. El curso de histología que diseñamos se estructuró en la plataforma Moodle, y los contenidos se propusieron en formato síncrono (zoom) y asíncrono (grabaciones). También incluimos el uso de herramientas gratuitas de microscopía virtual. Este estudio tuvo como objetivo investigar el impacto de un curso de histología e-learning en la satisfacción y el rendimiento de los estudiantes de medicina, enfermería y obstetricia. La muestra incluyó 424 estudiantes chilenos de medicina, enfermería y obstetricia de dos cohortes. Se aplicó una encuesta tipo Likert al final del curso. Se realizó un análisis exploratorio y una regresión por mínimos cuadrados ordinarios. En este estudio, presentamos una experiencia positiva de un curso de e-learning de histología. El análisis factorial exploratorio reveló tres factores principales relacionados con la "satisfacción sobre el aprendizaje e-learning", "clases presenciales versus clases virtuales" y el "diseño del curso y la calidad de la enseñanza". También encontramos que existía una relación positiva y significativa entre las percepciones de los estudiantes sobre la adaptación del curso de histología tradicional (presencial) a un formato e-learning y su rendimiento académico. Nuestro estudio muestra que los cursos de histología e-learning que integran clases teóricas y sesiones prácticas pueden ser una valiosa herramienta de enseñanza. Los responsables de la elaboración de planes de estudios y los profesores de histología deben tener en cuenta las limitaciones y ventajas de este tipo de enseñanza y sugerimos incorporar estos tres factores al diseño y la evaluación de los cursos de histología en línea.

Biomechanical effects of hemin and sildenafil treatments on the aortic wall of chronic-hypoxic lambs.

Introduction: Gestation under chronic hypoxia causes pulmonary hypertension, cardiovascular remodeling, and increased aortic stiffness in the offspring. To mitigate the neonatal cardiovascular risk, pharmacological treatments (such as hemin and sildenafil) have been proposed to improve pulmonary vasodilation. However, little is known about the effects of these treatments on the aorta. Therefore, we studied the effect of hemin and sildenafil treatments in the aorta of lambs gestated and raised at highlands, thereby subjected to chronic hypoxia. Methods: Several biomechanical tests were conducted in the descending thoracic aorta (DTA) and the distal abdominal aorta (DAA), assessing 3 groups of study of hypoxic animals: non-treated (Control) and treated either with hemin or sildenafil. Based on them, the stiffness level has been quantified in both zones, along with the physiological strain in the unloaded aortic duct. Furthermore, a morphological study by histology was conducted in the DTA. Results: Biomechanical results indicate that treatments trigger an increment of axial pre-stress and circumferential residual stress levels in DTA and DAA of lambs exposed to high-altitude chronic hypoxia, which reveals a vasodilatation improvement along with an anti-hypertensive response under this characteristic environmental condition. In addition, histological findings do not reveal significant differences in either structure or microstructural content. Discussion: The biomechanics approach emerges as a valuable study perspective, providing insights to explain the physiological mechanisms of vascular function. According to established results, alterations in the function of the aortic wall may not necessarily be explained by morphostructural changes, but rather by the characteristic mechanical state of the microstructural components that are part of the studied tissue. In this sense, the reported biomechanical changes are beneficial in mitigating the adverse effects of hypobaric hypoxia exposure during gestation and early postnatal life.

Molecules involved in the sperm interaction in the human uterine tube: a histochemical and immunohistochemical approach.

In humans, even where millions of spermatozoa are deposited upon ejaculation in the vagina, only a few thousand enter the uterine tube (UT). Sperm transiently adhere to the epithelial cells lining the isthmus reservoir, and this interaction is essential in coordinating the availability of functional spermatozoa for fertilization. The binding of spermatozoa to the UT epithelium (mucosa) occurs due to interactions between cell-adhesion molecules on the cell surfaces of both the sperm and the epithelial cell. However, in humans, there is little information about the molecules involved. The aim of this study was to perform a histological characterization of the UT focused on determining the tissue distribution and deposition of some molecules associated with cell adhesion (F-spondin, galectin-9, osteopontin, integrin αV/ß3) and UT's contractile activity (TNFα-R1, TNFα-R2) in the follicular and luteal phases. Our results showed the presence of galectin-9, F-spondin, osteopontin, integrin αV/ß3, TNFα-R1, and TNFα-R2 in the epithelial cells in ampullar and isthmic segments during the menstrual cycle. Our results suggest that these molecules could form part of the sperm-UT interactions. Future studies will shed light on the specific role of each of the identified molecules.

Histochemical and Immunohistochemical Methods for the Identification of Proteoglycans.

Proteoglycans (PGs) are non-fibrillar extracellular matrix (ECM) molecules composed by a protein core and glycosaminoglycan (GAG) chains. These molecules are present in all tissues playing essential structural, biomechanical, and biological roles. In addition, PGs can regulate cell behavior due to their versatility and ability to interact with other ECM molecules, growth factors, and cells. The distribution of PGs can be evaluated by histochemical and immunohistochemical methods. Histochemical methods aimed to provide a useful overview of the presence and distribution pattern of certain groups of PGs. In contrast, immunohistochemical procedures aimed the identification of highly specific target molecules. In this chapter we described Alcian Blue, Safranin O, and Toluidine Blue histochemical methods for the screening of PGs in tissue sections. Finally, we describe the immunohistochemical procedures for specific identification of PGs (decorin, biglycan, and versican) in formaldehyde-fixed and paraffin-embedded tissues.

A new interpretation of the human embryo drawings in Icones Embryonum Humanorum by Samuel Thomas Soemmerring.

In 1799, Samuel Thomas Soemmerring published the book Icones Embryonum Humanorum, which was one of the first attempts in history to sort out prenatal human development chronologically. Despite its importance for the anatomical sciences, there is little information about Icones. In this context, our objective was to identify and estimate the developmental age of the seven human embryos present in Icones Embryonum Humanorum by external morphological analysis and morphometry of the drawings using Image-J® software. First, the book was translated from Latin. Then, the developmental age was estimated by external morphological analysis and morphometry (greatest length) of the drawings using Image-J® software. The book is composed of 20 drawings of human embryos and fetuses from two life-size tables. According to the external features and morphometric analysis, there are seven embryos (drawings I-VII). The embryonic age (pf: post-fertilization age) of drawing I corresponds to day 29-31 pf; drawing II, to day 33-35 pf; drawing III, to day 37-40 pf; drawing IV, to day 42-45 pf; drawing V, to day 45-47 pf; drawing VI, today 47-50 pf; and drawing VII, to day 52-55 pf. There are differences between the development age estimated by Soemmerring and our analysis. These differences are probably due to the methodological and technical limitations of the eighteenth century.

Revisiting the Teleost Thymus: Current Knowledge and Future Perspectives.

The thymus in vertebrates plays a critical role in producing functionally competent T-lymphocytes. Phylogenetically, the thymus emerges early during evolution in jawed cartilaginous fish, and it is usually a bilateral organ placed subcutaneously at the dorsal commissure of the operculum. In this review, we summarize the current understanding of the thymus localization, histology studies, cell composition, and function in teleost fishes. Furthermore, we consider environmental factors that affect thymus development, such as seasonal changes, photoperiod, water temperature fluctuations and hormones. Further analysis of the thymus cell distribution and function will help us understand how key stages for developing functional T cells occur in fish, and how thymus dynamics can be modulated by external factors like photoperiod. Overall, the information presented here helps identify the knowledge gaps and future steps needed for a better understanding of the immunobiology of fish thymus.

F-Spondin Is the Signal by Which 2-Methoxyestradiol Induces Apoptosis in the Endometrial Cancer Cell Line Ishikawa.

The metabolite 2-methoxyestradiol (2ME) is an endogenous estrogen metabolite with potential therapeutic properties in reproductive cancers. However, the molecular mechanisms by which 2ME exerts its anticancer activity are not well elucidated. The purpose of this study was to determine the molecular signals associated with the apoptotic effects of 2ME in a human endometrial cancer cell line. Ishikawa cells were treated with non-apoptotic (0.1 µM) or apoptotic concentrations (5 µM) of 2ME, and 12 hours later mRNA levels for Scd2, Snx6, and Spon1 were determined by real-time PCR. We then investigated by immunofluorescence and Western blot the expression and distribution of F-spondin, encoded by Spon1, in Ishikawa cells treated with 2ME 5 µM at 6, 12, or 24 h after treatment. The role of estrogen receptors (ER) in the effect of 2ME on the Spon1 level was also investigated. Finally, we examined whether 2ME 5 µM induces cell death in Ishikawa cells pre-incubated with a neutralizing F-spondin antibody. Non-apoptotic or apoptotic concentrations of 2ME decreased Scd2 and increased Snx6. However, Spon1 was only increased with the 2ME apoptotic concentration. F-spondin protein was also increased at 12 and 24 h after 2ME treatment, while 2ME-induced Spon1 increase was independent of ER. Neutralization of F-spondin blocked the effect of 2ME on the cell viability. These results show that F-spondin signaling is one of the components in the apoptotic effects of 2ME on Ishikawa cells and provide experimental evidence underlying the mechanism of action of this estrogen metabolite on cancer cells.

2-Methoxyoestradiol impairs mouse embryo implantation via F-spondin.

The anti-implantation effects of high oestradiol (E2) concentrations could be mediated by E2 metabolites. Herein, we examined whether 2-methoxyoestradiol (2ME) impairs embryo implantation via its target protein F-spondin. Mice on Day 3 of pregnancy were treated with E2 concomitantly with the cathecol-O-methyl transferase inhibitor OR486 and the number of implanted embryos was recorded 5 days later. The effect of 2ME or 4-methoxyoestradiol (4ME) on embryo implantation was also investigated. Plasma and uterine levels of 2ME were measured 0.5, 1 or 3h after E2 treatment while the mRNA for spondin 1 (Spon1) and F-spondin were determined in the uterus 3, 6, 12 or 24h after 2ME treatment. Finally, the effect of a neutralising F-spondin antibody on the anti-implantation effect of 2ME was explored. OR486 blocked the anti-implantation effect of E2; 2ME, but not 4ME, affected embryo implantation. The 2ME concentration was increased after 0.5 and 1h in plasma and 3h in uterine fluid following E2 treatment. 2ME increased levels of Spon1 at 12 and 24h although F-spondin was increased at 12h. F-spondin antibody blocked the effect of 2ME on embryo implantation. We conclude that 2ME impairs mouse embryo implantation via activation of F-spondin in the uterus.

Distribution of extracellular matrix molecules in human uterine tubes during the menstrual cycle: a histological and immunohistochemical analysis.

The uterine tube (UT) is an important and complex organ of the women's reproductive system. In general, the anatomy and basic histology of this organ are well-known. However, the composition and function of the extracellular matrix (ECM) of the UT is still poorly understood. The ECM is a complex supramolecular material produced by cells which is commonly restricted to the basement membrane and interstitial spaces. ECM molecules play not only a structural role, they are also important for cell growth, survival and differentiation in all tissues. In this context, the aim of this study was to evaluate the deposition and distribution of type I and III collagens and proteoglycans (decorin, biglycan, fibromodulin and versican) in human UT during the follicular and luteal phases by using histochemical and immunohistochemical techniques. Our results showed a broad synthesis of collagens (I and III) in the stroma of the UT. The analysis by regions showed, in the mucosa, a specific distribution of versican and fibromodulin in the epithelial surface, whereas decorin and fibromodulin were observed in the lamina propria. Versican and decorin were found in the stroma of the muscular layer, whereas all studied proteoglycans were identified in the serosa. Curiously, biglycan was restricted to the wall of the blood vessels of the serosa and muscular layers. Furthermore, there was an immunoreaction for collagens, decorin, versican and fibromodulin in the UT peripheral nerves. The differential distribution of these ECM molecules in the different layers of the UT could be related to specific structural and/or biomechanical functions needed for the oviductal transport, successful fertilization and early embryogenesis. However, further molecular studies under physiological and pathological conditions are still needed to elucidate the specific role of each molecule in the human UT.

Encapsulation of human elastic cartilage-derived chondrocytes in nanostructured fibrin-agarose hydrogels.

The generation of elastic cartilage substitutes for clinical use is still a challenge. In this study, we investigated the possibility of encapsulating human elastic cartilage-derived chondrocytes (HECDC) in biodegradable nanostructured fibrin-agarose hydrogels (NFAH). Viable HECDC from passage 2 were encapsulated in NFAH and maintained in culture conditions. Constructs were harvested for histochemical and immunohistochemical analyses after 1, 2, 3, 4 and 5 weeks of development ex vivo. Histological results demonstrated that it is possible to encapsulate HECDC in NFAH, and that HECDC were able to proliferate and form cells clusters expressing S-100 and vimentin. Additionally, histochemical and immunohistochemical analyses of the extracellular matrix (ECM) showed that HECDC synthetized different ECM molecules (type I and II collagen, elastic fibers and proteoglycans) in the NFAH ex vivo. In conclusion, this study suggests that NFAH can be used to generate biodegradable and biologically active constructs for cartilage tissue engineering applications. However, further cell differentiation, biomechanical and in vivo studies are still needed.