Comparative Anatomy, Physiology, and Biochemistry of Mammalian Skin
David W. Hobson in Dermal and Ocular Toxicology, 2020
Another type of cell found in connective tissue is the macrophage. It is known by a variety of names such as clasmatocyte and histiocyte. The macrophage has been postulated to be derived from the monocyte. The life span may be 2 to 3 months, depending on the tissue. Macrophages can be identified by vital staining, an excellent method demonstrating macrophages “in action”. Ultrastructurally, macrophages have an irregular shape. Their cell membrane has been modified into finger-like projections or pseudopods. The nucleus is indented and common organelles such as mitochondria and a small amount of rough endoplasmic reticulum are present. Macrophages contain numerous types of lysosomes with pinocytotic and phagocytotic vacuoles. The function of macrophages is to engulf and destroy bacteria or foreign substances, and to process antigens for presentation to the immune system. The functional activity of a macrophage can be appreciated by the complexity of its membrane modifications.38,202,204
The Protozoa
Donald L. Price in Procedure Manual for the Diagnosis of Intestinal Parasites, 2017
The cytoplasm has two components, the outer tougher and more hyaline ectoplasm that forms the outer layer of amoebae (and other protozoa) and the inner, more fluid component, the endoplasm, that is granular and contains many of the organelles and any inclusions. In Plate 36:1, a clear pseudopodium of ectoplasm stretches out and, when actively motile, the amoeba flows into it. For food gathering, the pseudopodium simply surrounds its prey and draws it inside where it is surrounded by the cytoplasm and transferred to a vacuole such as the one surrounding the red blood cell in the drawing. The ingested material is digested while in the vacuole (see the smaller included body in a vacuole, Plate 36:1) and the wastes are extruded in much the same manner as the prey was included only in reverse.
Gastric Cytoprotection and Adaptation to Ethanol
Victor R. Preedy, Ronald R. Watson in Alcohol and the Gastrointestinal Tract, 2017
Fundus and corpus mucosa in humans consist of the test tube-like oxyntic glands draining into gastric pits. Oxyntic glands contain parietal cells secreting hydrochloric acid and intrinsic factor, chief cells producing pepsinogens and endocrine cells (most common are enterochromaffin-like cells) whose functions are still only partially elucidated. Regenerative zone occupies the neck area of oxyntic glands and consists of poorly differentiated mucus cells which differentiate and migrate at the same time. Cells migrating upward differentiate mostly into surface mucus cells (some also into parietal cells which are lost during migration before they reach pit area).16 Surface epithelium has a short life span. Cells migrating downward differentiate mostly into parietal, chief, and endocrine cells. All of them are characterized by a long life span. Cellular migration (and completed differentiation) within the gland requires an intact glandular basal membrane. Cells migrate by extending pseudopodia attached to basal membrane. Damage to the basal membrane affects the process of rapid restitution of surface epithelium.
A novel method for automated assessment of megakaryocyte differentiation and proplatelet formation
Published in Platelets, 2018
M. Salzmann, B. Hoesel, M. Haase, M. Mussbacher, WC. Schrottmaier, JB. Kral-Pointner, M. Finsterbusch, A. Mazharian, A. Assinger, JA. Schmid
Although we used murine MKs derived from bone marrow stem cells, this pipeline is likely to be also applicable for MKs derived from other sources. In our standardized routine, we used fibrinogen, which is localized to vascular sinusoids (21) and represents a sound inducer of murine proplatelet formation in vitro (12,32). However, other methods to induce proplatelets would be equally possible and compatible with our CellProfiler’s analysis, as long as fluorescent images of cell bodies and nuclei are analysed. The exact biological function of pseudopodia-forming MKs and spread MKs remains to be elucidated. However, we were able to observe a moderate reduction of pseudopodia-forming cells and a strong reduction of spread MKs after dasatinib treatment, indicating reduced MK function, leading to thrombocytopenia (17).
Tryptophan as a Safe Compound in Topical Ophthalmic Medications: In Vitro and In Vivo Studies
Published in Ocular Immunology and Inflammation, 2022
Anna Matysik-Woźniak, Waldemar A. Turski, Monika Turska, Roman Paduch, Mirosław Łańcut, Paweł Piwowarczyk, Mirosław Czuczwar, Robert Rejdak
Since IL-6 stimulated the migration of HCE in vitro,55,56 we investigated the effect of TRP on cell skeletal organization and motility. The morphological study showed that TRP did not influence the cellular cytoskeleton in vitro. Therefore, due to the fact that human corneal and conjunctival epithelium contain microvilli and filopodia, which are considered to provide motive force in cell migration and possibly stimulate the process of wound healing,59–61 we used pores of 0.4 μm. Transwell membranes with 3.0 μm or larger pores are usually used for cell invasion, chemotaxis, and motility studies. In our study, a considerably high increase of migrating pseudopodia-like projections in both tested epithelia was noted. TRP can affect the mobility of cells, which can heal the wound by growing in a more orderly manner than observed in samples where this amino acid was deficient. As a consequence, this type of re-epithelization may be more stable and characterized by a fully physiological epithelial lining as compared to wound healing without TRP presence. This may be also associated with an increase in the number of pseudopodia allowing the migration of cells toward the damage when TRP was added. However, this requires further detailed analyses, especially those related to the remodeling of the cellular cytoskeleton. These findings led us to determine the TRP effect in the wound healing of corneal erosions in vivo.
Leptin Promotes Prostate Cancer Proliferation and Migration by Stimulating STAT3 Pathway
Published in Nutrition and Cancer, 2021
Amal Gorrab, Alessandra Pagano, Khouloud Ayed, Mohamed Chebil, Amine Derouiche, Hervé Kovacic, Asma Gati
To analyze the impact of leptin on the epithelial-mesenchymal transition (EMT), an important process during tumor development by which epithelial cells acquire mesenchymal phenotype, we examined the morphology of cells and E-cadherin expression after treatment with 100 ng/ml of leptin. As shown in Figure 3(a), leptin treated DU-145 exhibit morphological differences when compared with untreated cells. The phenotypic changes included the acquisition of fibroblast-like appearance, theincreased formation of pseudopodia emanating from the cell membrane, the dissolution of cell-cell junction and the loss of apical-basolateral cell polarity. Additionally, leptin treated DU-145 cells downregulate E-cadherin expression. Treatment with AG490 inhibits morphological changes on leptin treated DU-145 cells and enhances upregulation of E-cadherin (Figure 3(b)). Totally, these results argue that leptin could enhance PC cells EMT.