Cancer Biology and Genetics for Non-Biologists
Trevor F. Cox in Medical Statistics for Cancer Studies, 2022
All living things are made up of cells, from the simple unicellular amoeba to the complex human composed of about 37 trillion () cells. Cells that contain a nucleus are called eukaryotic cells; cells without a nucleus are called prokaryotic cells. Bacteria are examples of prokaryotic cells. Humans are eukaryotes consisting of eukaryotic cells, such as bone, nerve and stem cells. In fact, there are about 200 types of cells in our bodies. Figure 2.1 shows a typical eukaryotic cell, illustrating its structure. Cells come in different shapes and sizes; neurons in the brain and nervous system are long and thin, blood cells are roughly spherical, some bone cells are cuboidal and columnar while others have many branches. The size of a red blood cell is , the size of a skin cell is , an ovum , whilst the length of some nerve cells can be over .
Fungi and Water
Chuong Pham-Huy, Bruno Pham Huy in Food and Lifestyle in Health and Disease, 2022
Fungi including mushrooms, molds, and yeasts are eukaryotic organisms as vegetable or animal species, but are classified as a separate kingdom because fungal cell walls contain rigid chitin and glucans that are not found in animal, vegetal, or bacterial species (1–8). Eukaryotic cells are cells that contain a nucleus and other organelles enclosed within membranes. In other words, the fungal kingdom comprises a hyper diverse clade of heterotrophic eukaryotes characterized by the presence of a chitinous cell wall, the loss of phagotrophic capabilities, and cell organizations that range from completely unicellular monopolar organisms to highly complex syncytial filaments (containing several nuclei) that may form macroscopic structures (8). Mushrooms like morels, button mushroom, and puffballs are macroscopic multicellular fungi, while molds are a large group of microscopic multicellular fungi. Molds are characterized by filamentous forms named hyphae. Many fungi occur not as hyphae but as unicellular forms called yeasts, which are invisible to the naked eye and reproduce by budding (2–4).
Small-Molecule Targeted Therapies
David E. Thurston, Ilona Pysz in Chemistry and Pharmacology of Anticancer Drugs, 2021
The cell cycle is the process that causes a cell to divide into two daughter cells. It includes the duplication of a cell’s DNA (i.e., DNA replication) and some of its organelles, and the partitioning of its cytoplasm and other components into two daughter cells. In eukaryotes, the cell cycle is divided into two main stages: the interphase and the mitotic (M) phase (including mitosis and cytokinesis). The interphase involves cell growth during which nutrients needed for mitosis are accumulated, and replication of the DNA and some organelles can occur. The mitotic phase involves the separation of replicated chromosomes and organelles, and cytoplasm, into two new daughter cells. Under normal control, the cell cycle (Figure 6.73) functions as a highly regulated process with several distinct phases: G0 (quiescence) followed by G1 (pre-DNA synthesis), S (DNA synthesis), G2 (pre-division), and M (cell division).
Role of PFKFB3-driven glycolysis in sepsis
Published in Annals of Medicine, 2023
Min Xiao, Dadong Liu, Yao Xu, Wenjian Mao, Weiqin Li
Under physiological conditions, PFKFB3 is expressed at low levels in a wide variety of cells and is responsible for stimulating glycolysis through the allosteric activation of PFK-1. It is essential for cell growth, differentiation and function. In sepsis, PFKFB3 is rapidly (approximately 6 h after LPS stimulation) increased and phosphorylated, which contributes to the rapidly increased glycolytic flux and subsequent inflammatory injury. On the one hand, PFKFB3-derived glycolysis promotes inflammatory activation of immune cells (macrophages and neutrophils), which induces inflammatory injury by releasing proinflammatory factors. On the other hand, it can induce inflammatory injury in ECs and promote lung fibroblast proliferation. Inhibition of PFKFB3 has additionally shown great potential in reducing inflammatory damage and improving the prognosis of sepsis. Therefore, efforts to understand PFKFB3 may provide a novel combinatorial therapeutic target for the effective treatment of sepsis.
Evaluation of the antimicrobial mechanism of biogenic selenium nanoparticles against Pseudomonas fluorescens
Published in Biofouling, 2023
Ying Xu, Ting Zhang, Jiarui Che, Jiajia Yi, Lina Wei, Hongliang Li
The integrity of the cell membrane is a key factor in bacterial growth. In normal cells, proteins are the main macromolecules present in the cell membrane. The cell membrane not only keeps the cell environment stable for energy and substance metabolism it also regulates and selects substances that enter and leave the cells. The integrity of the membrane can be assayed by the leakage of the cell contents. This study showed that that as the SeNPs concentration increased, the OD gradually increased, and the leakage of proteins and nucleic acids in P. fluorescens ATCC 13525 increased in a time-dependent manner. It was speculated that SeNPs reacted with thiols or sulfhydryl groups in phospholipid bilayer membrane proteins to denature and inactivate them, leading to the loss of the integrity of cell membrane and an increase in membrane permeability. Tareq et al. (2017) found that SeNPs promoted protein leakage from the bacterial cytoplasm, which was 6.10 μg mg−1 in the control group, while after treatment with SeNPs, it was increased to be 7.12 μg mg−1. The live/dead state of bacteria was observed by CLSM. It was found that the live cells gradually decreased and the dead cells increased when treated with SeNPs, indicating that the cell membrane was damaged. Similarly, Ning et al. (2021) found that phenyllactic acid significantly compromised the cell membrane integrity of P. fluorescens.
Cs-131 as an experimental tool for the investigation and quantification of the radiotoxicity of intracellular Auger decays in vitro
Published in International Journal of Radiation Biology, 2023
Pil M. Fredericia, Mattia Siragusa, Ulli Köster, Gregory Severin, Torsten Groesser, Mikael Jensen
As evident by the different ka and kout for HeLa and V79 cells, the kinetic time constants differ between the two cell types and so these constants will have to be determined individually as shown. However, the Na+/K+-ATPase, by which Cs-131 is transported, is present in the plasma membrane of all mammalian cells (Suhail 2010), and so the experimental setup can easily be used for other mammalian cell lines than HeLa and V79 cells. The transport of K+ across the cell membrane or cell wall is vital for an organism’s ability to maintain its membrane potential (Suhail 2010), and Cs-131 can be expected to be transported into other cell types or organisms, by a variety of K+ transporters. These cells/organisms include non-mammalian cells (Latorre and Miller 1983), bacteria (Zhang et al. 2014), algae (Avery et al. 1991, 1993) and fungi (Avery 1995).
Related Knowledge Centers
- Cytoplasm
- DNA
- DNA Repair
- Macromolecule
- Metabolite
- Protein
- Rna
- Small Molecule
- Electron Microscope
- Cell Membrane
- DNA
- Rna
- DNA Repair