Phenotype heterogeneity in dental pulp stem niches Perlea, Paula; Rusu, Mugurel Constantin; Didilescu, Andreea Cristiana ...
Romanian journal of morphology and embryology,
2016, Letnik:
57, Številka:
4
Journal Article
Dental stem niches (DSNs) reside in different dental tissues, being of particular importance in tissue engineering and dental regeneration procedures. The present paper aims to review the DSNs from ...the view of niche inhabitants, either extrinsic, such as cells of the myeloid lineage, or intrinsic, such as endothelial cells, perivascular cells and spindle-shaped stromal cells, e.g., telocytes. DSNs harbor different dental stem÷progenitor cell morphologies, in different stages of differentiation and with various potentialities, the angiogenic potential with respect to regenerative endodontic procedures being emphasized here. It seems therefore important to consider the DSNs as being heterogeneous, for a better understanding of an accurate identification of niche team players in regenerative medicine.
Sprouting angiogenesis is led by specialized cell--the endothelial tip cells (ETCs) which can be targeted by pro- or anti-angiogenic therapies. We aimed to perform a qualitative study in order to ...assess the guidance by tip cells of the endothelial sprouts in the repairing mucosa of the edentulous mandibular crest. Mucosa of the mandibular edentulous ridge was collected from six adult patients, prior to healing abutment placement (second surgery). Slides were prepared and immunostained with antibodies for CD34 and Ki67. The abundant vasculature of the lamina propria was observed on slides and the CD34 antibodies labeled endothelial tip cells in various stages of the endothelial sprouts. Ki67 identified positive endothelial cells, confirming the proliferative status of the microvascular bed. According to the results, the in situ sprouting angiogenesis is driven by tip cells in the oral mucosa of the edentulous ridge and these cells can be targeted by various therapies, as required by the local pathologic or therapeutic conditions.
Even though apoptosis is known to be associated with various cardiovascular pathologies, its presence in cardiac nodal tissue in adults was only scarcely researched. Cardiomyocyte apoptosis was ...associated with diabetic cardiovascular pathology. Our main objective was to test whether programmed cell death is present in nodal tissue in type II diabetes mellitus and, if present to characterize it. The study was designed as a qualitative one. We used autopsy samples of hearts from 10 patients (56 to 73-year-old, 6:4 male to female ratio), positive for type II diabetes mellitus. Samples from sinoatrial and atrioventricular nodes were stained with Hematoxylin-Eosin. For immunohistochemistry, we used primary antibodies for caspases 3 and 9, cathepsin B, and TRADD. Nodal tissue in all samples was characterized by diffuse interstitial fibrosis and chronic ischemic lesions; nuclear damage and foci of irreversible ischemic necrosis intermingled with isles of relatively morphologically normal myocytes. Sinoatrial and atrioventricular nodes were caspase-3 and -9 positive, and also cathepsin-B-positive, suggesting an overlap between apoptotic and necrotic mechanisms. Central area of the sinus node seemed to have the most severe lesions. As a conclusion, nodal apoptosis is present in nodal tissue in type II diabetes mellitus; it involves the intrinsic pathway and associated concomitant and/or post-apoptotic necrosis.
Cell death types are usually defined by morphological criteria. Even though podocyte loss is associated with various cell death mechanisms, podocyte apoptosis is rarely detected. The purpose of this ...study is to evaluate whether morphological signs of apoptotic cell death could be detected in early streptozotocin-induced diabetes in rats kidneys. There were used five Wistar rats, and renal tissue samples were drawn after three weeks of disease and further evaluated in transmission electron microscopy (TEM). Podocytes damage was indicated by two major findings: foot processes effacement, viewed as loss of cell processes, and chromatin condensation and margination (partial karyopyknosis: peculiar nuclear morphologies - partly normal, euchromatic, and partly positive for karyopyknosis and nuclear shrinkage). Mitotic glomerular endotheliocytes were also encountered. Podocytes cell death commitment and detachment appeared as concomitant events. However, karyopyknosis is not a specific feature of apoptosis. Thus, further biochemical evaluations are needed to distinguish between different pathways of podocytes death.
The sphenoid sinus is one of the most morphologically variable and surgically important structures of the skull base. Located below the sella turcica, neighbored by parasellar regions, such as the ...orbital apex, pterygopalatine fossa and lateral sellar region (cavernous sinus), it is clinically related to these and surgically relevant as corridor for various approaches. Moreover, at the sphenoethmoidal junction, important variations occur, most of these related to the presence of the Onodi cells and the intrasinusal protrusions of the optic nerve. That is why any identified and previously undescribed morphological variation at that level must be added to the well-established protocols, clinical and surgical. During a retrospective CT study of the sphenoid sinus anatomical features a previously unreported morphology was encountered and is reported here. It refers to a unilateral sphenoethmoid cell (SEC), Onodi-positive, not only overriding the superior aspect of the sphenoid but also its lateral side to get intimately related to the maxillary nerve. As that SEC expanded medially to the cavernous sinus apex, it altered the usual endosinusal morphological correlations and also added itself within the limits of the Mullan's triangle. It appears so that such postero-infero-lateral extended pneumatization of an Onodi cell alters the surgical landmarks and also can blur clinical pictures, by adding maxillary and pterygopalatine signs and symptoms.
