Odontogenesis, the development of teeth, is a complex, multistage process that unfolds from early embryogenesis through tooth eruption and maturation. It serves as a classical model of organogenesis due to the intricate reciprocal interactions between cranial neural crest-derived mesenchyme and oral epithelium. This narrative review synthesizes current scientific knowledge on human tooth development, tracing the journey from the embryological origins in the first branchial arch to the formation of a fully functional tooth and its supporting structures. Key morphogenetic stages—bud, cap, bell, apposition, and root formation—are described in detail, highlighting the cellular events and histological features characterizing each stage. We discuss the molecular and cellular regulatory networks that orchestrate odontogenesis, including the conserved signaling pathways (Wnt, BMP, FGF, SHH, EDA) and transcription factors (e.g., PAX9, MSX1/2, PITX2) that drive tissue patterning and cell differentiation. The coordinated development of supporting periodontal tissues (cementum, periodontal ligament, alveolar bone, gingiva) is also examined as an integral part of tooth organogenesis. Finally, developmental anomalies (such as variations in tooth number, size, and form) and the fate of residual embryonic epithelial cells are reviewed to underscore the clinical significance of developmental processes. Understanding the normal course of odontogenesis provides crucial insight into congenital dental disorders and lays a foundation for advances in regenerative dental medicine.

A significant factor that affects the value of the Ki-67 proliferation index (IK) is the interpretation and implementation approach. This method is based on visual or automated methods to count tumor nuclei labeled with Ki-67 antigen, and is prone to errors. Detection of Ki-67 is a useful tool in breast cancer and contributes to its molecular classification. The current study proposes a method for the quantification of Ki-67-positive tumor nuclei, which allows for the determination of the exact IK value that is required for tumor stratification based on the proliferation rate. The IK was assessed in 81 successive cases of diagnosed invasive ductal breast carcinoma using a semi-automated method that accurately identifies positive tumor cell nuclei. This method prevents the inclusion of other possible positive cells, including lymphoid, normal epithelia and hyperplastic. In small specimens with increased cell density, where the nucleus/cytoplasm ratio is markedly in favor of the nucleus and the distance between nuclei is small, the method allows precise quantification of the nuclei, even when the limits between nuclei are difficult to identify. In addition, images may be stored in a database, including the assessments, and easily accessed when required. We hypothesize that the semi-automated method for counting nuclei offers the most accurate method of assessing the IK and avoids counting errors that may occur through other methods.

Placental dysfunction underlies the major obstetric syndromes, including preeclampsia, fetal growth restriction, placenta accreta spectrum, pregnancy loss, and monochorionic twin complications. Recent molecular studies have revealed that dysregulated oxygen sensing, impaired angiogenic signaling, altered immune tolerance, and defective trophoblast fusion represent shared pathogenic pathways that converge across these disorders. Integrating morphological evidence with mechanistic data highlights how villous maldevelopment, shallow trophoblast invasion, and aberrant vascular remodeling translate into clinical disease. Advances in biomarker research have already transformed clinical care: the sFlt-1/PlGF ratio is now established in the prediction and management of preeclampsia, while placental proteins such as PAPP-A and PP13, nucleic acid signatures including cfDNA, cfRNA and miRNAs, and extracellular vesicle cargo show promising potential for early, non-invasive detection of placental pathology. Multi-omics approaches, particularly single-cell and spatial transcriptomics combined with proteomic and metabolomic profiling, are paving the way for composite diagnostic panels that capture the polygenic and multicellular nature of placental disease. This review synthesizes current knowledge of molecular mechanisms, histological correlates, and translational biomarkers, and outlines how precision obstetrics may emerge from bridging mechanistic discoveries with clinical applications.

The reciprocal relationship between coping mechanisms and lung cancer diagnosis: findings of a prospective study Cristian Oancea,1 Cristian Suciu,2 Bogdan Timar,3 Ion Papava,4 Marius Raica,2 Ovidiu Burlacu5 1Department of Pulmonology, 2Department of Microscopic Morphology/Histology, 3Department of Biostatistics and Medical Informatics, 4Department of Neurosciences, 5Department of Surgical Semiology, â??Victor Babesâ?? University of Medicine and Pharmacy, Timisoara, Romania Background/purpose: Lung cancer is a major stress factor for the affected individual, leading to psychological distress in over 50% of the diagnosed patients. Since coping styles describe different patterns in approaching serious problems, our study aimed at ascertaining if the diagnosis of lung cancer has an impact on the patientâ??s coping styles and if there is a difference in psychical response among patients with different coping styles, as assessed by variance of anxiety and depression scores after diagnosis. Patients and methods: In this prospective study, a cohort of 50 patients were evaluated using the COPE scale, Generalized Anxiety Disorder Questionnaire 7 (GAD-7), and Patient Health Questionnaire-9 (PHQ-9), both prior to and 1 month after learning about their lung cancer diagnosis. The baseline and the final parameters were compared and stratified with respect to coping styles.Results: We observed that 1 month after learning the diagnosis, the patients had a significantly higher GAD-7 score (median score 12 vs 4 points; p

Hematopoietic stem cells have a remarkable plastic capacity, which allows them to differentiate into various cells, such as immune cells, nervous cells, muscle cells, bone and cartilaginous cells. The aim of this study was to show the capacity of stem cells to differentiate into endothelial cells, in culture, after addition of endothelial cells growth suplement (ECGS). We also compared the behavior of these cells with that of endothelial cells obtained from human umbilical vein (HUVEC). CD34+ cells obtained by immunomagnetic separation from human umbilical cord and placental blood were used. After 12‐15 days of culture in a medium containing ECGS, the cells showed morphological changes characteristic to endothelial cells and immunocytochemical analysis revealed the presence of CD31 surface antigen and von Willebrand factor. The flow‐cytometric analysis of endothelial cells adhesion molecules (ECAM) showed that endothelial cells derived from CD34+ cells expressed CD54/ICAM‐1 9.65 ± 0.2% and CD106/VCAM 7.73±0.3%, values similar to those expressed by HUVECs. After TNF incubation, ECAM expression increased only in HUVECs. These data demonstrate that a fraction of circulating CD34+ cells may develop some endothelial cell characteristics when cultured with ECGS, but they are functionally different from HUVECs.