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Introduction to Cells, DNA, and Viruses
Published in Patricia G. Melloy, Viruses and Society, 2023
One of the biggest functions of the cell is to produce proteins to do particular jobs for cells and the body as a whole. Because humans contain so many kinds of cells, we have separation of function for different groups of cells, which are organized into tissues, organs, and organ systems. Cells duplicate themselves when they are actively dividing. Cells go through a series of steps known as the cell cycle, in which the cell prepares for DNA synthesis, then copies its DNA, then separates the DNA in the form of the chromosomes moving to opposite sides of the cell (see Figure 1.1). The cell then completes nuclear division followed by separation of the cytoplasmic contents, resulting in two cells. This process is known as mitosis. Not all cells are actively dividing, but cell division is critical during development as well as to replenish worn-out tissues in an adult organism. When cells do a particular job for the body, they need to create proteins encoded in the DNA. Cells come in many shapes and sizes, but what they all have in common is the procedure needed to convert the hereditary material to functional protein in the body.
The Fight Against Cancer
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
Cells undergo a regular cycle of cell division, which is split into three periods. Interphase comprises the majority of the cell cycle, when there is no division, and is subdivided into a further three parts: first growth phase (G1), where organelles produce proteins, synthesis phase, when DNA is replicated, and second growth phase (G2), when organelles grow and divide and energy stores are increased. The second phase is nuclear division, where the nucleus divides into either two (mitosis) or four (meiosis). The last phase is cell division to produce the daughter cells. For mammals, the cell cycle takes about 24 hours, 90% of which is interphase. Most cancers are caused by damage to the genes that regulate mitosis and the cell cycle.
Basic Cell Biology
Published in Kedar N. Prasad, Handbook of RADIOBIOLOGY, 2020
This kind of nuclear division occurs only in the germinal cells (ovary and testis). In the testis during meiosis, each member of a paired chromosome duplicates, and the duplicated members come to lie side by side in a four-stranded configuration. The successive nuclear divisions result in the formation of four sperm, each with a haploid set of chromosomes (half of the parent cell). During meiosis, the first nuclear division is a mitotic one in which each daughter cell receives an identical set of diploid chromosomes. The second nuclear division is a reduction division in which each daughter cell contains only the haploid set of chromosomes. Diagrammatic representations of meiosis in the testis and ovary are shown in Figures 2.3 and 2.4. In the testis, spermatogonia divide by mitosis to form primary spermatocytes, which undergo reduction division to form spermatids. Spermatids have a haploid set of chromosomes. The spermatids undergo a maturation process to form spermatozoa. The entire process of the formation of spermatoza is called spermatogenesis. The basic process of meiosis in the female is the same, except that each oocyte gives rise to only one functional egg, whereas each spermatocyte produces four functional spermatozoa. The process of forming the functional egg is called oogenesis.
Identification of stemness subtypes and features to improve endometrial cancer treatment using machine learning
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2023
Xiaoqin Lu, Yanqi Ying, Wenyi Zhang, Rui Li, Wuliang Wang
Next, we further analysed the function and pathway of the DEG enrichment data to obtain the GO terms and KEGG enrichment pathways. GO analysis included biological process (BP), Cellular Component (CC), and Molecular function (MF). We conducted GO and KEGG enrichment analysis for 287 differentially expressed genes and set the screening criteria as q value <0.05 (Supplementary Table 8 & Supplementary Table 9). We sorted the q values and used a bubble graph to show the top 30 significant BP, CC, and MF terms (Figure 4(D)). The enriched BP terms included organelle fission, nuclear division, and mitotic nuclear division. The spindle, chromosomal region, chromosome region, and centromeric region were the enriched CC terms. Enzyme inhibitor activity, peptidase regulator activity, and tubulin binding were the enriched MF terms. After analysis, seven pathways were identified as and meaningful. The bubble diagram in Figure 4(E) shows all the enriched pathways; the significantly enriched pathways include cell cycle and oocyte meiosis.
Bilateral multicenter pseudohemangiomatous interstitial hyperplasia of the breast: a case report
Published in Case Reports in Plastic Surgery and Hand Surgery, 2023
Microscopically, PASH of the breast is histologically characterized by anastomoses and collagenous stroma with slit-like spaces and is lined by flattened, spindle-shaped cells. These clear spaces, which may mimic microscopic vascular channels, do not contain red blood cells. Sometimes, for an accurate diagnosis, an IHC examination is also needed. The mesenchymal cells of PASH express vimentin, CD34 (an endothelial cell marker), actin, desmin, calponin, and progesterone receptor, but not CD31 (vascular marker) or factor VIII (endothelial cell marker) [5,12,19]. In this case, the patient had an enlargement of the collagen fibers in the breasts, in which many fissures were formed and coincided with each other. The center of the cleft spindle cells had a mild morphology and negligible heterozygosity, and no nuclear division was observed. Mesenchymal cells tested positive for CD34 but not CD31; however, the peripheral vascular tissue tested positive for CD31. Therefore, the combination of morphology and IHC in this PASH diagnosis was well established.
Development of a novel gene signature to predict prognosis and response to PD-1 blockade in clear cell renal cell carcinoma
Published in OncoImmunology, 2021
Xiaomao Yin, Zaoyu Wang, Jianfeng Wang, Yunze Xu, Wen Kong, Jin Zhang
To find the key module most correlated with clinical traits, we performed WGCNA on TCGA cohort extracting robust DEGs derived from the RRA analysis. Clinical information was retrieved from TCGA (Figure 2a). After setting soft-thresholding value as 6 (scale free R2 = .87, mean connectivity = 11.10) and cut height as 0.20, eight co-expression modules were eventually identified (Figure 2b-d). According to the heatmap of module-trait relationships, green module demonstrates the highest correlations with clinical traits (Figure 2e; R2 = .35 and P = 2e−16 with pathologic stage, R2 = .38 and P = 6e−20 with tumor grade, R2 = .31 and P = 2e−13 with vital status). Module significance analysis further validated that green module is the highest correlated module with survival status of ccRCC patients (Figure 2f). Herein, we determined green module as the key module. GO and KEGG analyses were conducted to obtain further insight into biological function of genes within the key module. Based on adjust P value, top ten significant GO terms for biological process, molecular function and cellular component, as well as KEGG pathways, are shown in Figure S2. The results implied that genes in the key module are mainly involved in mitotic cell cycle, nuclear division and organelle fission.