Finding a Target
Nathan Keighley in Miraculous Medicines and the Chemistry of Drug Design, 2020
Organelles perform different roles in the cell. The mitochondria are responsible for energy generation. Through the process of respiration, they manufacture adenosine triphosphate (ATP); a source of chemical energy. Modification of selected molecules is undertaken at the Golgi apparatus and/or the endoplasmic reticulum. Molecules manufactured by the cell, or assimilated from outside, may need to be changed to make them suitable for a given biochemical process. The Golgi apparatus and endoplasmic reticulum are the organelles with the capacity to perform this role. The nucleus, as previously mentioned, is where DNA is contained and is the control centre for the cell. Having a porous membrane enables passage of selected molecules to facilitate communication between the nucleus and the rest of the cell to ensure that instructions are received for the essential biochemical process of the cell to continue functioning without error.
Ultrastructure of Human Gastrointestinal System. Interactions Among Mast Cells, Eosinophils, Nerves and Muscle in Human Disease.
William J. Snape, Stephen M. Collins in Effects of Immune Cells and Inflammation on Smooth Muscle and Enteric Nerves, 2020
MC are mononuclear cells filled with secretory granules1 (Figures 20 & 21). Other cytoplasmic organelles include mitochondria, intermediate filaments, lipid bodies, Golgi structures, small vesicles, and ribosomes. Surface processes are narrow folds. The granules are filled with dense materials, assuming several patterns. These include homogeneously dense material, scrolls, crystals, particles, and mixtures of these patterns.1 These granule patterns in aggregate are unique to human MC. MC that are present in situ in normal gastrointestinal tissues,5 as well as those examined after isolation from human colons,29 are well-preserved cells which generally contain scroll-filled and particle-filled granules. MC that are present in, or isolated from, the gut contain more particle-filled granules than do MC from other locations.1,5,29 MC from the lung, for example, contain more scroll granules;6,7,22 those from skin contain more crystal granules.30,31
Introduction to Cells, DNA, and Viruses
Patricia G. Melloy in Viruses and Society, 2023
Cellular macromolecules are organized into compartments called organelles (like little organs) that have an organization allowing for the work of the cell to happen. So, like organs such as the heart and lungs that have a special role in the body, organelles have a special role inside the cell. Some examples of key cellular organelles include the nucleus (where DNA is housed), mitochondria (energy generation), and ribosomes (protein production). Except for the nucleolus residing in the nucleus, organelles are found in what is known as the cytoplasm or cytosol of the eukaryotic cell. The nucleus is an important organelle because it acts as the central control point for all the activities of the cell. The nucleus houses most of the cell’s DNA in the form of protein/DNA structures known as chromosomes that allow for condensation of the large amount of genetic material in each cell (Alberts et al. 2019). Cell division occurs in a process known as mitosis, in which the chromosomes are copied and separated equally between the two daughter cells. Later, we will talk about organelles that help move or traffic things around the cell, as well as into and out of the cell. Trafficking-related organelles include the endoplasmic reticulum, Golgi apparatus, and vesicles. Viruses can exploit the cellular trafficking network to move into and out of the cell.
Correlation between replicative senescence of endometrial gland epithelial cells in shedding and non-shedding endometria and endometriosis cyst during menstruation
Published in Gynecological Endocrinology, 2018
Cong-Xiang Yu, Jing-Hui Song, Yue-Fei Li, Ya Tuo, Jing-Jing Zheng, Rui-Jing Miao, Fei Wang, Jing Liu, Lei Liang
A biological cytology study revealed that the organelle structure determines cell function [1]. Furthermore, abnormal gene expression affects the structure and function of cells [11]. An organelle is a functional structure packaged by various membranes in cells, which plays an important role in biological metabolism. Changes in organelle morphological structure have a close correlation with its function. Cheng and Zhang [12] revealed that uterine artery infusion chemotherapy can change the ultrastructures of cervical tumor cells, and change cell function. Weijun Wu [13] revealed that nitric oxide synthase can change mitochondria and part of other organelles in middle cerebral artery endothelial cells and smooth muscle cells of rabbits. Mitochondria provide energy to cells through oxidative phosphorylation, and increasing its amount can enhance the function of ATP synthesis in the membrane. Hence, changes in its energy metabolism is one of the signs of tumorigenesis. A study concluded that if the endometrium can adhere, invade and grow in a ‘foreign area’, its organelles must have some unique changes [14].
Sub-lethal effects of thiamethoxam on Apis mellifera Linnaeus
Published in Toxin Reviews, 2022
Amit Choudhary, Bharathi Mohindru, Ashok Kumar Karedla, Jaspal Singh, Pardeep K. Chhuneja
Thiamethoxam (0.04 ng µL−1 day−1) has been reported to cause of cytoplasm vacuolization, increased apocrine secretion, and cell elimination in midgut digestive and regenerative cells (Oliveira et al.2013). This caused the cytotoxic effects in the midgut through alterations of the nuclei, mitochondria, and rough endoplasmic reticulum. These may compromise the cellular energy and protein production organelles (Catae et al.2014). Such effects were more pronounced after one day of exposure. The next stage is the discharge of toxicant into the hemolymph and there it alters the ultrastructure of the Malpighian tubules, i.e. degeneration of the mitochondria and microvilli. This reduced the excretion of toxicants and caused the death of the insect. In addition to these, thiamethoxam (0.001 ng µL−1) affected the Kenyon cells of the brain. Overall this affected the longevity of the bees (Friol et al.2017). Alterations in optic lobes have also been reported after feeding the sub-lethal doses of thiamethoxam to the larvae of Africanized honey bees (Tavares et al.2015). This caused the death of the cells in the optic lobes leading to a reduction in the number of neurons. Any reduction in the number of neurons, if not reestablished, may cause disorientation of adult bees. In a chronic exposure experiment, Overmyer et al. (2017) reported 0.12 ng µL−1 sucrose solution to be the No Observed Effect Concentration (NOEC) for adults of A. m. ligustica.
Testing efficacy of the nicotine protection of the substantia nigra pars compacta in a rat Parkinson disease model. Ultrastructure study
Published in Ultrastructural Pathology, 2022
S A M Elgayar, Ola A Hussein, Heba A Mubarak, Amany M Ismaiel, Asmaa M.S. Gomaa
In group I, astrocytes revealed pale nuclei that are usually regular in shape and surrounded by a scanty cytoplasm that is generally less electron dense than that of neurons (Figure 6A). Their cytoplasm contains few organelles including elongated mitochondria, free ribosomes, and scanty endoplasmic reticulum, glycogen granules and bundles of intermediate filaments. Oligodendrocytes generally possess dark nuclei with condensed chromatin and their somata usually make direct contact with the neurons (Figure 6B). Microglia are either perivascular or parenchymal in position. They possess small heterochromatic nuclei surrounded by scanty dense cytoplasm with long thick processes (Figure 6C). Their somata are always separated from those of the neurons by astrocytic processes.
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