The Biological Characteristics of Continuous Cell Lines Derived from Human Bladder
George T. Bryan, Samuel M. Cohen in The Pathology of Bladder Cancer, 2017
In some of the cell lines, such as RT4, the initial culture contained epithelioid and fibroblastic cells, but the succeeding cultures contained only epithelioid cells.5 RT4 cells are large and polygonal with well-defined margins. The cytoplasm is foamy and many of the cells contain glycogen granules. Electron microscopic (EM) studies show that most cells have irregular ovoid nuclei and resemble basal or intermediate cells. However, occasional cells, particularly at the periphery of a cell clump, have rounded nuclei and resemble superficial cells. Microvilli are present on many cells. The mitochondria vary in size, shape, and matrix density. Free ribosomes are present, but rough endoplasmic reticulum is rare. Prominent zones of Golgi apparatus and cytoplasmic vesicles are also present in most cells, but lysosomes and multivesicular bodies are uncommon.5
Structure and function of the mesothelial cell
Wim P. Ceelen, Edward A. Levine in Intraperitoneal Cancer Therapy, 2015
Mesothelial cells are generally morphologically similar, regardless of their anatomical site and species (Figure 2.1a). In general, they exhibit an elongated, flattened, and squamous morphology, approximately 25 μm in diameter, with a central oval nucleus and characteristic apical microvilli and occasional cilia [2]. The microvilli vary in length and density between adjacent cells and different organs that may reflect functional adaptation [2,3]. The role of the microvilli is to increase the surface area of the cells to enhance absorption and secretion and prevent frictional injury to the mesothelial cells. They are also likely to be involved in a variety of other cellular functions such as regulation of energy metabolism, gating of ion flux, generation and modulation of membrane potential, Ca2+ signaling, and mechanoreception [4].
Comparative Anatomy, Physiology, and Biochemistry of Mammalian Skin
David W. Hobson in Dermal and Ocular Toxicology, 2020
Apocrine glands are large, simple coiled tubular structures. The name apocrine is inappropriate because it was once thought that the apical portion of the cell was lost during secretion; however, electron microscopy has shown that the secretion is actually a product of the cell and that no cytoplasm is lost during the secretory process. The secretory portion of this gland consists of cuboidal to columnar cells which rest on the myoepithelial cells or on the basement membrane. In areas of the basement membrane which are devoid of myoepithelial cells, the plasmalemma of the secretory cell is highly convoluted. This folded area could provide for an exchange of metabolites. The apical portion of this cell has microvilli on its surface. Organelles are prominent, especially the Golgi apparatus which is usually located on the apical side of the nucleus. Mitochondria are located both on the basal side and apical side of the nucleus. They are greatly enlarged and have a homogeneous granular matrix. Large, dense granules are located on the apical side of the Golgi region and vary in size, density, and homogeneity. Rough endoplasmic reticulum and tonofilaments are abundant. Adjacent secretory cells are connected by junctional complexes.229
Effect of erythromycin on the ultrastructure of human macrophages exposed to cigarette smoke extract in vitro
Published in Ultrastructural Pathology, 2022
Shaoshuang Wang, Jianjun Huo, Yanlin Wei, Mei Huan, Zhouling Luo, Meihua Li, Mingzhi Wen, Xiaoning Zhong, Zhiyi He, Nan Ma, Jufeng Qiu, Xiaojuan Tang
Abnormal changes in the cellular ultrastructure of macrophages in the CSE group were apparent. However, following treatment with EM, the abnormal ultrastructure of the CSE+EM group had almost returned to normal. The general ultrastructure of human macrophages is displayed in Figure 1. In the control group (Figure 1A) the majority of the cells were rounded or oval-shaped, with a small number of mitochondria and lysosomes, and the rough endoplasmic reticulum (ER) was visible. Microvilli-like projections were present on the majority of the cell surface. The nucleus was eccentric, circular, oval or kidney-shaped, (there were few irregularly-shaped nuclei), and the chromatin was concentrated at the nuclear membrane. In the CSE group (compared with the control group), not only had the number of lysosomes, mitochondria and vacuoles increased, as well as an increase in the ER network, but the cellular ultrastructure was also altered; this included mitochondrial swelling and vacuolization, lysosomal gathering, expansion of the rough ER, and the aggregation of electron-dense granules. Additionally, the chromatin was concentrated in the nucleus (Figure 1B).
Redox modulatory protective effects of ω-3 fatty acids rich fish oil against experimental colitis
Published in Toxicology Mechanisms and Methods, 2019
Mohita Sharma, Ramanpreet Kaur, Kuldeep Kaushik, Naveen Kaushal
To obtain an accurate picture of DSS induced lesions and protective effects of FO (if any), ultrastructural studies were performed with the help of scanning electron microscope at magnification 370× and 500×. The mucosal surface of colon in FO and CO groups (Figure 5(A,B)) appeared to be subdivided by well-defined concave grooves, and regular-shaped crypt openings containing mucin like material. Microvilli are regular and goblet cells are interspersed among enterocytes and appeared as small point like and slightly depressed cavities. On the contrary, the DSS + CO group (Figure 5(D,F)) showed degenerated epithelium, severe inflammatory cell infiltration, widened grooves, dilatations of glandular crypts losing their regular shape by assuming fissure like aspects and depletion of goblet cells, leaving an irregular crater like area were evident. Supplementation with FO, following DSS treatment (Figure 5(C,E)) significantly restored the architecture of the colon epithelium with a marked decrease in inflammatory cell infiltration compared with the DSS + CO group animals.
Targeting the intestinal lymphatic system: a versatile path for enhanced oral bioavailability of drugs
Published in Expert Opinion on Drug Delivery, 2018
Renuka Suresh Managuli, Sushil Yadaorao Raut, Meka Sreenivasa Reddy, Srinivas Mutalik
Small intestine consists of four tissue layer: i) innermost mucosa layer which is involved in nutrients absorption from partly digested food (chyme); ii) middle submucosa layer consists of nerves, blood, and lymphatic vessels which transport nutrients from intestine to rest of the body; iii) down to submucosa layer exists the muscularis layer consisting of several layers of smooth muscle tissues which aids in contraction of small intestine, and iv) outermost is the serosa layer which along with the mesentery surrounds the intestine. The interior wall of the small intestine is in the form of circular folds and the epithelial lining of the mucosal layer is protruded into finger like projections known as villi (singular: villus). Around 20,000 villi are present per square inch of mucosa [13]. The epithelial cells in the small intestine comprising enterocytes (absorptive cells), goblet cells, paneth cells, enteroendocrine cells, and tuft cells are held together by tight junctions forming a barrier and they possess a brush border surface onto them known as microvilli [14]. The circular folds and projections (villi and microvilli) increase the intestinal surface area thereby offering maximum contact between epithelial cells and chyme for optimum absorption of nutrients.
Related Knowledge Centers
- Absorption
- Actin
- Cell Adhesion
- Cytoplasm
- Mechanotransduction
- Microfilament
- Secretion
- Organelle
- Fimbrin
- Villin-1