Intercellular contacts at the epithelial—mesenchymal interface of the developing rat submandibular gland in vitro

Development ◽  
1977 ◽  
Vol 39 (1) ◽  
pp. 71-77
Author(s):  
Leslie S. Cutler
Keyword(s):  
Electron Microscopy ◽  
Submandibular Gland ◽  
Functional Differentiation ◽  
Developmental Sequence ◽  
Millipore Filter ◽  
Intercellular Contacts ◽  
Rat Submandibular Gland ◽  
Developing Rat

An ultrastructural study of the development of the rat submandibular gland (SMG) anlage in vitro was undertaken to determine if epithelial-mesenchymal and epithelial-nerve contacts were integral events in the differentiation of the gland in vitro as they are in vivo. SMG rudiments were removed at the stalk-bulb stage (15 days in utero) and cultured for 6 days on a millipore filter in supplemented McCoy's 5A media. Rudiments were taken at daily intervals, fixed and processed for electron microscopy. The overall development of the explanted rudiments closely paralleled their maturation in vivo although cultured glands lagged 24–36 h behind their normal counterparts. Direct epithelial-mesenchymal contacts were seen after the morphogenetic patterning of the gland had been established but prior to functional differentiation of the rudiment. Epithelial-nerve contacts were not seen although healthy axons were seen in the stroma throughout the culture period. The study indicates that epithelial-nerve contacts are probably not required for morphogenesis of cytodifferentiation of the rat SMG. However, direct epithelial-mesenchymal contacts appear to be an integral part of the developmental sequence of the rat SMG.

Morphogenesis and functional differentiation of the rat parotid gland in vivo and in vitro

Development ◽  
1970 ◽  
Vol 24 (2) ◽  
pp. 411-424
Author(s):  
Kirstie A. Lawson
Keyword(s):  
Submandibular Gland ◽  
Amylase Activity ◽  
Functional Differentiation ◽  
Basal Nucleus ◽  
Early Postnatal Development ◽  
Rat Parotid ◽  
Terminal Buds ◽  
Branched Structure

In comparison with the submandibular and the sublingual glands, the parotid develops slowly in the rat. The foetal rudiment appears a day later than that of the submandibular gland and the formation of adenomeres is slower, leading to a more diffusely branched structure. Cytodifferentiation, in the form of traces of mucopolysaccharide in the tubules and terminal buds, begins at, or just before, birth. There is a transitory increase in mucopolysaccharide production for a few days after birth until the presumptive acinar cells become pyramidal in shape with basal nucleus and granular cytoplasm. Amylase activity of the gland begins to rise between the second and third day after birth and reaches the adult level at weaning. That of the submandibular gland remains at the foetal level. Parotid rudiments were cultivated on a film of agar over a medium of fowl plasma and chick embryo extract. The oxygen in the gas phase of air and 5% CO2 was increased to 50% after the first 9 days in vitro. Under these conditions the mass of the rudiments increased tenfold during 18 days cultivation and the initially unbranched rudiment formed adenomeres in which the cytodifferentiation followed the same course as in vivo. The rise in amylase activity of the explants was only slightly delayed compared with that in vivo, suggesting that systemic or environmental factors are not obligatory in the early postnatal development of the rat parotid.

Cytochemical Evidence for Presynatic β-Adrenergic Regulation of Secretion in the Developing Rat Submandibular Gland

1977 ◽  
Vol 35 ◽  
pp. 430-431
Author(s):  
L.S. Cutler
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Submandibular Gland ◽  
Neonatal Rat ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Parotid Glands ◽  
Adrenergic Agonist ◽  
Rat Submandibular Gland

Many studies previously have shown that the B-adrenergic agonist isoproterenol and the a-adrenergic agonist norepinephrine will stimulate secretion by the adult rat submandibular (SMG) and parotid glands. Recent data from several laboratories indicates that adrenergic agonists bind to specific receptors on the secretory cell surface and stimulate membrane associated adenylate cyclase activity which generates cyclic AMP. The production of cyclic AMP apparently initiates a cascade of events which culminates in exocytosis. During recent studies in our laboratory it was observed that the adenylate cyclase activity in plasma membrane fractions derived from the prenatal and early neonatal rat submandibular gland was retractile to stimulation by isoproterenol but was stimulated by norepinephrine. In addition, in vitro secretion studies indicated that these prenatal and neonatal glands would not secrete peroxidase in response to isoproterenol but would secrete in response to norepinephrine. In contrast to these in vitro observations, it has been shown that the injection of isoproterenol into the living newborn rat results in secretion of peroxidase by the SMG (1).

scholarly journals Potassium (86Rb+) efflux from the rat submandibular gland under sodium-free conditions in vitro.

1989 ◽  
Vol 416 (1) ◽  
pp. 503-515 ◽  
Author(s):  
D L Bovell ◽  
H Y Elder ◽  
J D Pediani ◽  
S M Wilson
Keyword(s):  
Submandibular Gland ◽  
Rat Submandibular Gland

scholarly journals Assessment of SnFe2O4 Nanoparticles for Potential Application in Theranostics: Synthesis, Characterization, In Vitro, and In Vivo Toxicity

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 825
Author(s):  
Saman Sargazi ◽  
Mohammad Reza Hajinezhad ◽  
Abbas Rahdar ◽  
Muhammad Nadeem Zafar ◽  
Aneesa Awan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
A549 Cells ◽  
In Vitro Cytotoxicity ◽  
Hek293 Cells ◽  
Hydrothermal Route ◽  
X Ray ◽  
Tin Chloride ◽  
Bet Analysis

In this research, tin ferrite (SnFe2O4) NPs were synthesized via hydrothermal route using ferric chloride and tin chloride as precursors and were then characterized in terms of morphology and structure using Fourier-transform infrared spectroscopy (FTIR), Ultraviolet–visible spectroscopy (UV-Vis), X-ray power diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and Brunauer–Emmett–Teller (BET) method. The obtained UV-Vis spectra was used to measure band gap energy of as-prepared SnFe2O4 NPs. XRD confirmed the spinel structure of NPs, while SEM and TEM analyses disclosed the size of NPs in the range of 15–50 nm and revealed the spherical shape of NPs. Moreover, energy dispersive X-ray spectroscopy (EDS) and BET analysis was carried out to estimate elemental composition and specific surface area, respectively. In vitro cytotoxicity of the synthesized NPs were studied on normal (HUVEC, HEK293) and cancerous (A549) human cell lines. HUVEC cells were resistant to SnFe2O4 NPs; while a significant decrease in the viability of HEK293 cells was observed when treated with higher concentrations of SnFe2O4 NPs. Furthermore, SnFe2O4 NPs induced dramatic cytotoxicity against A549 cells. For in vivo study, rats received SnFe2O4 NPs at dosages of 0, 0.1, 1, and 10 mg/kg. The 10 mg/kg dose increased serum blood urea nitrogen and creatinine compared to the controls (P < 0.05). The pathology showed necrosis in the liver, heart, and lungs, and the greatest damages were related to the kidneys. Overall, the in vivo and in vitro experiments showed that SnFe2O4 NPs at high doses had toxic effects on lung, liver and kidney cells without inducing toxicity to HUVECs. Further studies are warranted to fully elucidate the side effects of SnFe2O4 NPs for their application in theranostics.

scholarly journals Cemp1-p3 Peptide Promotes the Transformation of Octacalcium Phosphate into Hydroxyapatite Crystals

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1131
Author(s):  
Maricela Santana ◽  
Gonzalo Montoya ◽  
Raúl Herrera ◽  
Lía Hoz ◽  
Enrique Romo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Octacalcium Phosphate ◽  
Sequence Motifs ◽  
Simple Method ◽  
Transmission Electron ◽  
Precursor Phase ◽  
Mineralized Tissues ◽  
Potent Growth

Dental cementum contains unique molecules that regulate the mineralization process in vitro and in vivo, such as cementum protein 1 (CEMP1). This protein possesses amino acid sequence motifs like the human recombinant CEMP1 with biological activity. This novel cementum protein 1-derived peptide (CEMP1-p3, from the CEMP1’s N-terminal domain: (QPLPKGCAAVKAEVGIPAPH), consists of 20 amino acids. Hydroxyapatite (HA) crystals could be obtained through the combination of the amorphous precursor phase and macromolecules such as proteins and peptides. We used a simple method to synthesize peptide/hydroxyapatite nanocomposites using OCP and CEMP1-p3. The characterization of the crystals through scanning electron microscopy (SEM), powder X-ray diffraction (XRD), high--resolution transmission electron microscopy (HRTEM), and Raman spectroscopy revealed that CEMP1-p3 transformed OCP into hydroxyapatite (HA) under constant ionic strength and in a buffered solution. CEMP1-p3 binds and highly adsorbs to OCP and is a potent growth stimulator of OCP crystals. CEMP1-p3 fosters the transformation of OCP into HA crystals with crystalline planes (300) and (004) that correspond to the cell of hexagonal HA. Octacalcium phosphate crystals treated with CEMP1-p3 grown in simulated physiological buffer acquired hexagonal arrangement corresponding to HA. These findings provide new insights into the potential application of CEMP1-p3 on possible biomimetic approaches to generate materials for the repair and regeneration of mineralized tissues, or restorative materials in the orthopedic field.

Reepithelialization of Orthotopic Tracheal Allografts Prevents Rejection after Withdrawal of Immunosuppression

2005 ◽  
Vol 114 (4) ◽  
pp. 279-288 ◽  
Author(s):  
Satish Govindaraj ◽  
Elena Fedorova ◽  
Eric M. Genden ◽  
Houtan Chaboki ◽  
Jonathan S. Bromberg ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cyclosporine A ◽  
Allograft Rejection ◽  
Lymphocyte Subpopulation ◽  
Ciliated Epithelium ◽  
Prior Work ◽  
Cellular Infiltrate ◽  
Tracheal Transplantation

Prior work has demonstrated that immunosuppressed orthotopic tracheal allografts undergo progressive reepithelialization over a 48-day period with recipient-derived tracheal epithelium. We hypothesized that reepithelialization of tracheal allografts would prevent rejection after withdrawal of immunosuppression. BALB/c murine tracheal grafts were transplanted orthotopically into either syngeneic or allogeneic C57/BL6 recipients. The recipients were either not immunosuppressed, immunosuppressed with cyclosporine A (10 mg/kg per day) continuously, or immunosuppressed for 48 days and then withdrawn from immunosuppression. The grafts were assessed for acute and chronic rejection 10 days and 50 days after immunosuppression withdrawal. The immunosuppressed allograft recipients maintained a ciliated epithelium acutely and chronically after immunosuppression withdrawal. Ten days after immunosuppression withdrawal, there was a mild cellular infiltrate, which resolved 50 days after withdrawal. Electron microscopy, lymphocyte subpopulation assays, and lamina propria analysis demonstrated that immunosuppression withdrawal did not result in tracheal allograft rejection. In vitro and in vivo assessments did not demonstrate evidence of systemic or local immune tolerance. We conclude that reepithelialization of orthotopic tracheal allografts with recipient-derived mucosa prevents rejection of allograft segments. Tracheal transplantation may require only transient immunosuppression, which can be withdrawn after tracheal reepithelialization.

In vivo and in vitro Study of V Uptake in Developing Rat Molar Enamel

1980 ◽  
Vol 59 (10) ◽  
pp. 1643-1648 ◽  
Author(s):  
J.W. Bawden ◽  
T.G. Deaton ◽  
M. Chavis
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Developing Rat ◽  
Rat Molar

scholarly journals ELECTRON MICROSCOPY OF PLASMA-CELL TUMORS OF THE MOUSE

1961 ◽  
Vol 9 (2) ◽  
pp. 369-381 ◽  
Author(s):  
D. F. Parsons ◽  
M. A. Bender ◽  
E. B. Darden ◽  
Guthrie T. Pratt ◽  
D. L. Lindsley
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Complex Structure ◽  
Granular Body ◽  
Virus Particles ◽  
Culture Cells ◽  
Large Numbers ◽  
Tumor Agent

The X5563 tumor has been grown in tissue culture. Cells similar to those of the original tumor migrated from the explant and attached to the glass walls of the culture vessels. Electron microscopy showed that large numbers of particles, similar in morphology to virus particles, were associated with these cells after 7 days of culture. The two principal types of particles found in the tumor in vivo appear to be present in vitro. Many more of these particles, however, were larger and showed a more complex structure. Whereas the particles were mainly localized inside endoplasmic reticulum or the Golgi zone in the tumors in vivo, in the tissue culture the majority of the particles were associated with the plasma membrane and were found outside of the cells. The relation of the particles to the granular body is discussed as well as a possible relation to the mammary tumor agent.

scholarly journals Human Islet Amyloid Polypeptide Fibril Binding to Catalase: A Transmission Electron Microscopy and Microplate Study

2010 ◽  
Vol 10 ◽  
pp. 879-893 ◽  
Author(s):  
Nathaniel G. N. Milton ◽  
J. Robin Harris
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Islet Amyloid Polypeptide ◽  
Amyloid Β ◽  
Human Islet ◽  
Islet Amyloid ◽  
Human Islet Amyloid Polypeptide ◽  
Transmission Electron

The diabetes-associated human islet amyloid polypeptide (IAPP) is a 37-amino-acid peptide that forms fibrilsin vitroandin vivo. Human IAPP fibrils are toxic in a similar manner to Alzheimer's amyloid-β (Aβ) and prion protein (PrP) fibrils. Previous studies have shown that catalase binds to Aβ fibrils and appears to recognize a region containing the Gly-Ala-Ile-Ile sequence that is similar to the Gly-Ala-Ile-Leu sequence found in human IAPP residues 24-27. This study presents a transmission electron microscopy (TEM)—based analysis of fibril formation and the binding of human erythrocyte catalase to IAPP fibrils. The results show that human IAPP 1-37, 8-37, and 20-29 peptides form fibrils with diverse and polymorphic structures. All three forms of IAPP bound catalase, and complexes of IAPP 1-37 or 8-37 with catalase were identified by immunoassay. The binding of biotinylated IAPP to catalase was high affinity with a KDof 0.77nM, and could be inhibited by either human or rat IAPP 1-37 and 8-37 forms. Fibrils formed by the PrP 118-135 peptide with a Gly-Ala-Val-Val sequence also bound catalase. These results suggest that catalase recognizes a Gly-Ala-Ile-Leu—like sequence in amyloid fibril-forming peptides. For IAPP 1-37 and 8-37, the catalase binding was primarily directed towards fibrillar rather than ribbon-like structures, suggesting differences in the accessibility of the human IAPP 24-27 Gly-Ala-Ile-Leu region. This suggests that catalase may be able to discriminate between different structural forms of IAPP fibrils. The ability of catalase to bind IAPP, Aβ, and PrP fibrils demonstrates the presence of similar accessible structural motifs that may be targets for antiamyloid therapeutic development.

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