The Importance of Mesenchymal Factors in the Differentiation of Chick Epidermis

Development ◽  
1961 ◽  
Vol 9 (3) ◽  
pp. 370-384
Author(s):  
C. B. McLoughlin
Keyword(s):  
Epithelial Cells ◽  
Connective Tissue ◽  
Squamous Epithelium ◽  
The Other ◽  
Β Cells ◽  
Preen Gland ◽  
Other Hand ◽  
Stratified Squamous Epithelium

It is well established that in the developing chick the underlying mesenchyme initiates the appearance of specific epidermal derivatives, e.g. feathers (Sengel, 1956), claws (Cairns & Saunders, 1954), and the preen gland (Gomot, 1958). On the other hand, it is not yet known to what extent the epidermis is independent of mesenchymal intervention for its basic differentiation into a stratified, squamous epithelium. Sobel's (1958) work on the 8-day chick pituitary suggests that the differentiation and multiplication of certain epithelial cells cannot proceed in the absence of mesenchymal elements. She found that the isolated epithelial cells of the hypophysial rudiment survived but were unable to differentiate or multiply; when associated with perichondrial fibroblasts, however, they resumed mitosis and produced typical α and β cells. In the first part of the present investigation, experiments were made to see whether the embryonic epidermis, like the hypophysial epithelium, requires the resence of fibroblasts to enable it to grow and differentiate, or whether it can proliferate, acquire its characteristic squamous structure and keratinize, when isolated and cultivated in the absence of connective tissue.

Note on the Transformation of Ciliated into Stratified Squamous Epithelium as a result of the Application of Friction

1890 ◽  
Vol 16 ◽  
pp. 119-120 ◽  
Author(s):  
John Berry Haycraft ◽  
E. W. Carlier
Keyword(s):  
Mucous Membrane ◽  
Squamous Epithelium ◽  
The Other ◽  
Ciliated Epithelium ◽  
Deep Groove ◽  
Stratified Squamous Epithelium ◽  
Trachealis Muscle

(Abstract.)In man, in the rabbit, and some other animals the trachea is built up of a series of cartilaginous rings incomplete behind; the rings being completed in this position by the trachealis muscle.The mucous membrane forms a smooth cylindrical lining for the whole tube, and is covered by a ciliated epithelium.In the cat and dog the cartilage rings completely encircle the trachea, and overlap posteriorly, and the trachealis muscle, which is well developed, is placed outside the cartilage, and has a powerful action in varying the diameter of the tube.When this muscle contracts the overlapping ends of the cartilage ride one upon another, and the projecting ends form a vertical ridge down the inside of the trachea, which can be readily seen on slitting the organ open. This ridge is separated by a deep groove from the other end of the plate.

Histologic Analysis of the Oral Mucosa Lining Osseointegrated Implant Cover Screws: A Study in Humans

2010 ◽  
Vol 36 (1) ◽  
pp. 3-10
Author(s):  
André Alan Nahas ◽  
Paula Dechichi ◽  
Denildo de Magalhães ◽  
Andreia Espíndola Vieira
Keyword(s):  
Connective Tissue ◽  
Dental Implants ◽  
Oral Mucosa ◽  
Squamous Epithelium ◽  
Histologic Analysis ◽  
Morphologic Characteristics ◽  
Osseointegrated Implant ◽  
Oral Environment ◽  
Stratified Squamous Epithelium ◽  
Clinical Conditions

Abstract Osseointegrated dental implants are inserted into the alveolar ridge, and for them to function as tooth replacements, the surrounding tissues need to adapt to them. Just as with teeth, dental implants traverse the oral mucosa and have access to the contaminated environment of the oral cavity. Therefore, periodontal and peri-implant tissues are important for establishing a protective barrier. The aim of the present study was to perform a histologic analysis of the mucosa surrounding osseointegrated implant cover screws. For this study, 17 mucosal specimens were obtained from 12 patients during the second surgical session for implant exposure to the oral environment. After histologic preparation, specimens were sectioned perpendicularly to the mucosal surface to a thickness of about 3 µm, stained with 1% toluidine blue, and examined under light microscopy. All specimens showed a keratinized, stratified, squamous epithelium with well-defined strata. In the lamina propria, unorganized dense connective tissue was noted in the reticular layer, and in 4 samples, a chronic inflammatory infiltrate was seen in this region. The papillary layer presented tall connective papillae consisting of loose connective tissue. The results of this study confirm the hypothesis that the mucosa that conceals osseointegrated implant cover screws has the same morphologic characteristics as the alveolar masticatory mucosa. Furthermore, clinical conditions of normality in peri-implant tissues may not coincide with situations of histologic normality.

Lymphocystis tumours in the red mullet (Mullus surmuletus L.)

1951 ◽  
Vol 30 (2) ◽  
pp. 315-332 ◽  
Author(s):  
J. S. Alexandrawicz
Keyword(s):  
Connective Tissue ◽  
Blood Vessels ◽  
Microscopic Examination ◽  
Squamous Epithelium ◽  
Small Cells ◽  
Pectoral Fins ◽  
Red Mullet ◽  
Mullus Surmuletus ◽  
Stratified Squamous Epithelium

A specimen of the red mullet (Mullus surmuletus L.), caught in Plymouth waters in October 1949, was found to have tumours projecting externally on the pectoral fins. They were spherical or elliptical in shape, the largest being 20 mm. long. On the suggestion of Mr G. A. Steven some of these outgrowths were cut out and given to the writer for microscopic examination.When examined fresh they appear to consist of small, spherical, cyst-like bodies of various diameters, but there was no obvious clue as to their nature. After fixing in Bouin and sectioning, they are seen to be composed of cells of various sizes (PI. I, figs. 1–4). It can be seen that these cells lie close to one another, leaving only a little space for the embedding connective tissue which is characterized by the abundance of its own small cells. The blood vessels met with in this tissue contain fish erythrocytes. The whole is covered by stratified squamous epithelium (PI. I, fig. 2).

scholarly journals Intracranial Epidermoid Cysts in Three Dogs

1982 ◽  
Vol 19 (6) ◽  
pp. 646-650 ◽  
Author(s):  
J. N. Kornegay ◽  
E. J. Gorgacz
Keyword(s):  
Medulla Oblongata ◽  
Fourth Ventricle ◽  
Cerebellopontine Angle ◽  
Squamous Epithelium ◽  
Incidental Finding ◽  
The Other ◽  
Neurologic Dysfunction ◽  
Epidermoid Cysts ◽  
Stratified Squamous Epithelium ◽  
Intracranial Epidermoid

Intracranial epidermoid cysts were identified within the fourth ventricle of three dogs. The cysts measured up to 2.5 cm in diameter, were lined by stratified squamous epithelium, and contained intraluminal keratinaceous debris. Secondary compression of the medulla oblongata and cerebellum caused neurologic dysfunction in two dogs; the cyst was an incidental finding in the other dog. Similarities between these dogs and three previously reported intracranial epidermoid cysts in dogs included an apparent predilection for young dogs and involvement of the cerebellopontine angle, fourth ventricle, or both.

scholarly journals Soft Tissue Reconstruction with Free Gingival Graft Technique following Excision of a Fibroma

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Nurcan Tezci ◽  
Suleyman Emre Meseli ◽  
Burcu Karaduman ◽  
Serap Dogan ◽  
Sabri Hasan Meric
Keyword(s):  
Case Report ◽  
Connective Tissue ◽  
Squamous Epithelium ◽  
Alveolar Bone ◽  
Periodontal Treatment ◽  
Soft Tissue Reconstruction ◽  
Free Gingival Graft ◽  
Tissue Reconstruction ◽  
Stratified Squamous Epithelium ◽  
Gingival Graft

Background. Oral fibromas are benign, asymptomatic, smooth surfaced, firm structured tumoral lesions that originate from gingival connective tissue or periodontal ligament. Histologically, they are nodular masses characterized by a dense connective tissue, surrounded by stratified squamous epithelium.Case Report. This case report includes the clinical, radiographical, and histological findings and periodontal treatment of a 38-year-old female patient having painless swelling on the gingiva. Intraoral examination revealed a fibrotic, sessile, smooth surfaced gingival overgrowth interdentally between the teeth #13 and #14. Radiographical findings were normal. Initial periodontal treatment (IPT) was applied including oral hygiene instructions, scaling, and root planing. Following IPT, the lesion (0.7 × 0.6 × 0.4 cm) was excised and examined histopathologically. Subsequently, flap operation was performed to have an access to alveolar bone. Surgical site was reconstructed with free gingival graft obtained from hard palate. Hematoxylin-eosin stained sections revealed a nodular mass composed by dense collagen fibers in lamina propria covered by a stratified squamous epithelium, which were consistent with fibroma. Gingival healing was uneventful and without any recurrence during the 12-month follow-up.Conclusions. In order to achieve optimal functional and aesthetical outcomes, free gingival graft can be used for the reconstruction of the wound site after the excision of the fibroma.

scholarly journals 31. Histological of Tractus Digestivus of Domestical Catfish (Clarias batracus)

2019 ◽  
Vol 13 (2) ◽  
Author(s):  
Aliman Irfandi ◽  
Cut Dahlia Iskandar ◽  
Zainuddin Zainuddin ◽  
Dian Masyitha ◽  
Fitriani Fitriani ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Blood Vessels ◽  
Lamina Propria ◽  
Alimentary Tract ◽  
Squamous Epithelium ◽  
Goblet Cells ◽  
Taste Buds ◽  
Muscularis Mucosa ◽  
Club Cells ◽  
Stratified Squamous Epithelium

Domestical catfish is grouped into omnivora, although the fish is tended into carnivora.  The aim of the present study was to investigate histology of alimentary tract of domestical catfish (Clarias batrachus). In order to determine alimentary tract of domestical catfish, oesophagus, gastric and intestines is investigated by Haematoxilin Eosin. Histology exploration was performed each layer of alimentary tract’s wall consist of lamina epithelia, propria, and muscularis mucosa. Collagen connective tissue was developed tunica submucosa. The muscle of tunica muscularis was performed circular and elongated. Dense connective tissue and blood vessels was located in the tunica serosa. Histology exploration revealed has stratified squamous epithelium, mucosit cells, eosinophilic club cells on the lamina epithelia, and taste buds on the lamina propria in oesophagus. Gastric was establised simple prismatic cells, and glands of gastric on the lamina propria. Furthermore intestine was showed villi and goblet cells. There were not showed Brunner and Liberkhun gland. In conclusion, histology of alimentary tract was revealed from tunica mucosa, submucosa, and serosa.

The Ability to Differentiate, and the Size of Regenerated Cells, after repeated Regeneration in Spongilla lacustris

1953 ◽  
Vol s3-94 (26) ◽  
pp. 177-184
Author(s):  
H. V. BRONDSTED
Keyword(s):  
Epithelial Cells ◽  
The Body ◽  
The Other ◽  
Entire Body ◽  
Other Hand ◽  
The Individual ◽  
Basal Epithelial Cells

The findings presented here have a bearing on regeneration in general. They show that even in simply organized animals, the number of totipotent cells which are able to differentiate decreases as the individual ages. In older specimens it takes longer for the totipotent cells to differentiate than in younger ones; at the same time the nuclear and cytoplasmic volume of these cells is reduced. The expanded basal epithelium of sponges germinating from gemmules is an organ necessary to establish the tension in the body which is indispensable for the functioning of the sponge. Sponges that have germinated from gemmules can be forced to regenerate a basal epithelium. The materials for this regeneration is furnished by the archaeocytes, which are embryonic, totipotent amoebocytes. The number of archaeocytes that are able to perform this regeneration decreases with time, i.e. as the differentiation of the entire body proceeds. On the other hand, the ability of the sponge to expand repeatedly on its own basal epithelium after being pushed away from it is limited only by the onset of cytolysis. The ability of the archaeocytes to regenerate new typical basal epithelial cells is reduced after repeated regeneration. The size of both nucleus and cytoplasm is reduced more and more during repeated regeneration. The nucleo-cytoplasmic ratio is thus kept fairly constant.

CORTISOLWIRKUNGEN AUF DEN PROTEINUND ENERGIESTOFFWECHSEL IN DER PERIPHERIE

1968 ◽  
Vol 59 (2) ◽  
pp. 193-202
Author(s):  
H. Kröner ◽  
W. Staib
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Energy Consumption ◽  
Connective Tissue ◽  
Oxidative Metabolism ◽  
The Other ◽  
Other Hand ◽  
Inhibition Of Protein Synthesis ◽  
Short Time ◽  
Rna And Dna

ABSTRACT By measuring protein, RNA and DNA in skeletal muscle and spleen we were unable to demonstrate an enhanced catabolism due to cortisol. On the other hand we could demonstrate a reduced anabolism by diminished incorporation of 14C labelled leucin in protein of muscle, spleen and skin. Simultaneously an increase of ATP and an equivalent decrease of ADP were found in connective tissue, which were regarded as a consequence of reduced energy consumption. In skeletal muscle a decrease of energy consumption due to cortisol was only indirect demonstrable by reduced glycolysis when oxidative metabolism was eliminated for a short time. It seems obvious, that inhibition of protein synthesis causes the diminished energy consumption.

scholarly journals Pathogenesis of Digestive Tract Lesions in Duck Plague

1975 ◽  
Vol 12 (5-6) ◽  
pp. 349-361 ◽  
Author(s):  
S. J. Proctor
Keyword(s):  
Epithelial Cells ◽  
Digestive Tract ◽  
Squamous Epithelium ◽  
Fluorescent Microscopy ◽  
Intestinal Crypt ◽  
Viral Antigens ◽  
Cytoplasmic Vacuoles ◽  
Submucosal Glands ◽  
Stratified Squamous Epithelium ◽  
Viral Maturation

White Pekin ducklings were inoculated orally with duck plague virus. Tissues from the digestive tract were collected daily after inoculation and examined by light, electron and fluorescent microscopy. There were necrosis and degeneration of stratified squamous epithelium of the esophagus and cloaca, epithelium of intestinal crypt and esophageal submucosal glands, macrophages in the lamina propria, and submucosal fibrocytes and lymphocytes. Submucosal hemorrhages occurred after degeneration and necrosis of lymphocytes, macrophages, fibrocytes and epithelial cells. Viral antigens were detected in all these cells by use of fluorescein-labeled antibodies. With the electron microscope, nucleocapsids were seen in the nuclei, budding through the inner nuclear membrane; enveloped virions were present in cytoplasmic vacuoles of macrophages, epithelial cells and fibrocytes. In lymphocytes, nucleocapsids were also in the nuclei, but karyorrhexis and cytolysis occurred before viral maturation was completed.

The effects of experimental uremia in rats on duodenal VIP levels and the interaction of VIP with duodenal epithelial cells

1989 ◽  
Vol 9 (2) ◽  
pp. 207-212
Author(s):  
M. D. Fernández-Moreno ◽  
E. Arilla ◽  
J. C. Prieto
Keyword(s):  
Epithelial Cells ◽  
Cyclic Amp ◽  
Vasoactive Intestinal Peptide ◽  
Binding Affinity ◽  
Specific Binding ◽  
The Other ◽  
Receptor Level ◽  
Vip Receptors ◽  
Other Hand

The effects of experimental uremia on the concentration of vasoactive intestinal peptide (VIP) in duodenum as well as on the interaction of this neuropeptide with the corresponding epithelial cells were studied in rats. Duodenal VIP concentration was significantly decreased in uremic rats as compared to control animals. The specific binding of VIP to duodenal epithelial cells increased in rats with uremia due to an increase in the number of VIP receptors rather than a change in the binding affinity or in the extent of VIP degradation. On the other hand, the efficacy but not the potency of VIP upon cyclic AMP generation varied in parallel to that observed at the receptor level.

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