Search results for "Histology"
showing 10 items of 985 documents
Time-related changes in size of nuclei of pinealocytes in rats
1981
In a study of 96 adult male Sprague-Dawley rats, da- and time-related changes of the mean nuclear volume of pinealocytes were determined with the aim of testing the reproducibility of the karyometric findings described by Quay and Renzoni (1966). It is shown (i) that statistically significant differences exist between the central and peripheral mean volumes of pinealocyte nuclei/group of animals and time point (p less than 0.001), (ii) that the day and time related differences are statistically different in both regions (p less than 0.001), (iii) that in the center and periphery of the pineal body different diurnal patterns exist, and (iv) that the diurnal patterns are not parallel in the t…
The Odyssey of Hsp60 from Tumor Cells to Other Destinations Includes Plasma Membrane-Associated Stages and Golgi and Exosomal Protein-Trafficking Mod…
2012
BACKGROUND: In a previous work we showed for the first time that human tumor cells secrete Hsp60 via exosomes, which are considered immunologically active microvesicles involved in tumor progression. This finding raised questions concerning the route followed by Hsp60 to reach the exosomes, its location in them, and whether Hsp60 can be secreted also via other mechanisms, e.g., by the Golgi. We addressed these issues in the work presented here. PRINCIPAL FINDINGS: We found that Hsp60 localizes in the tumor cell plasma membrane, is associated with lipid rafts, and ends up in the exosomal membrane. We also found evidence that Hsp60 localizes in the Golgi apparatus and its secretion is prevent…
ANP (Atrial Natriuretic Peptide) presence in the heart of a tunicate, Ciona intestinalis.
2010
Atrial natriuretic peptide was found in the heart of vertebrates, we studied the ANP presence in the heart of Ciona intestinalis. This is animal is very important because of the its evolutionary position between invertebrates and vertebrates. ANP presence was only revealed in myoepithelial cells of the myocardium. Results suggest the hypothesis that ANP is present not only in the vertebrates but also in the invertebrates and in Ciona heart ANP might play a similar role like in the heart of vertebrates.
TGF-β superfamily signaling is essential for tooth and hair morphogenesis and differentiation
2007
Members of the transforming growth factor beta (TGF-beta) superfamily of signaling molecules are involved in the regulation of many developmental processes that involve the interaction between mesenchymal and epithelial tissues. Smad7 is a potent inhibitor of many members of the TGF-beta family, notably TGF-beta and activin. In this study, we show that embryonic overexpression of Smad7 in stratified epithelia using a keratin 5 promoter, results in severe morphogenetic defects in skin and teeth and leads to embryonic and perinatal lethality. To further analyze the functions of Smad7 in epithelial tissues of adult mice, we used an expression system that allowed a controlled overexpression of …
Adipose tissue, angiogenesis and angio-MIR under physiological and pathological conditions.
2019
Angiogenesis is a crucial process for the maintenance of normal tissue physiology and it is involved in tissue remodeling and regeneration. This process is essential for adipose tissue maintenance. The adipose tissue is composed by different cell types including stromal vascular cells as well as adipose stem cells (ASCs). In particular, ASCs are multipotent somatic stem cells that are able to differentiate and secrete several growth factors; they are recently emerging as a new cell reservoir for novel therapies and strategies in many diseases. Several studies suggest that ASCs have peculiar properties and participate in different disease-related processes such as angiogenesis. Furthermore, …
Cell fate specification in an in vitro model of neural development
1998
We have studied in an in vitro model of neural development the effect of neighboring cells on the fate of single fluorescently labeled precursor cells. In one line of experiments, PCC7-Mz1 embryonal carcinoma cells were transiently transfected with "green fluorescent protein" (GFP) and, following incubation with 0.1 microM all-trans retinoic acid (RA), the number and morphology of derivatives (neuronal or non-neuronal) was determined that form groups of GFP-expressing cells in a surrounding of unlabeled cells. Because single PCC7-Mz1 cells can produce single-lineage and mixed-lineage derivatives, they are individually pluripotent. In another line of experiments, we have analyzed the fate of…
Expression of protein kinase C gene family members is temporally and spatially regulated during neural development in vitro.
1998
We used primary cultures of rat hippocampal neurons and PCC7-Mz1 cells to correlate the expression of the protein kinase C (PKC) gene family with specific events during neural differentiation. Multipotent PCC7-Mz1 embryonic carcinoma stem cells develop into a tissue-like pattern of neuronal, fibroblast-like and astroglial cells by all-trans retinoic acid (RA) treatment. Western blot analyses demonstrate that PKCalpha, betaI, gamma, theta, mu, lambda, and zeta were constitutively expressed but the expression of PKCbetaII, delta, epsilon, and eta was up-regulated three days after addition of RA when cells mature morphologically. While the protein levels of the PKC isoforms betaII, delta and e…
Electron microscopic demonstration of intracelluar promethazine accumulation sites by a precipitation technique: application to the cerebellar cortex…
1996
A method is described that allows electron microscopic identification of the phenothiazine neuroleptic promethazine after supravital intracardiac injection of high drug concentrations (greater than or equal to 3 %). The cerebellar cortex of the mouse was used for the investigation. This procedure is based on simultaneous fixation of drug and tissue by immersion in a paraformaldehyde-glutaraldehyde solution with the addition of phosphomolybdic acid. The electron microscopic investigation revealed that the drug could easily be identified as an electron-dense precipitate. Subpopulations of neurons exhibited a higher affinity for the drug than others, but no preference for any nerve cell type …
Ontogenetic development of the holocephalan dentition: Morphological transitions of dentine in the absence of teeth.
2021
Among the cartilaginous fishes (Chondrichthyes), the Holocephali are unique in that teeth are absent both in ontogeny and adult regenerative growth. Instead, the holocephalan dentition of ever-growing nonshedding dental plates is composed of dentine, trabecular in arrangement, forming spaces into which a novel hypermineralized dentine (whitlockin) is deposited. These tissue features form a variety of specific morphologies as the defining characters of dental plates in the three families of extant holocephalans. We demonstrate how this morphology changes through ontogenetic development with continuity between morphologies, through successive growth stages of the dentition represented by the …
Neurons of the dentate molecular layer in the rabbit hippocampus.
2012
The molecular layer of the dentate gyrus appears as the main entrance gate for information into the hippocampus, i.e., where the perforant path axons from the entorhinal cortex synapse onto the spines and dendrites of granule cells. A few dispersed neuronal somata appear intermingled in between and probably control the flow of information in this area. In rabbits, the number of neurons in the molecular layer increases in the first week of postnatal life and then stabilizes to appear permanent and heterogeneous over the individuals' life span, including old animals. By means of Golgi impregnations, NADPH histochemistry, immunocytochemical stainings and intracellular labelings (lucifer yellow…