General Radiation Cytopathology
George W. Casarett in Radiation Histopathology, 2019
After the temporary mitotic block has ended, there is resumption of mitotic activity and return of the mitotic index toward normal levels, generally earlier at the lower dose levels than at the higher dose levels. Because of the differential phase flux inhibition, most of the cells blocked in the G2 phase, together with some of the cells that were in earlier phases of the cell cycle at the time of irradiation and reached the G2 phase during the G2 block, may go into mitotic division more or less together, which results temporarily in a supranormal mitotic index. The detection of the temporary supranormal mitotic index depends on the time intervals selected for sampling and analysis of the cells. This effect represents partial synchronization of the cell population with respect to cell generation cycle phases.
Diarrhea and Malnutrition
Fima Lifshitz in Childhood Nutrition, 2020
With the advent of the peroral jejunal biopsy technique, the histological features of the small intestine in a malnourished child have been extensively studied. Morphological studies show a striking spectrum of alterations ranging from severe damage to none at all. The picture that emerges from most of the studies is that in marasmus the small intestinal mucosa, although thin, was regarded to be virtually normal.108 The mitotic index was found to be significantly decreased.109 In kwashiorkor the mucosal architecture was found to be severely abnormal,110 although the mitotic index was only moderately reduced.111 As a result of these findings, it was postulated that cell renewal processes are more sensitive to calorie deficit rather than the overall availability of protein. It should be remembered that food in the intestinal lumen is one of the most important trophic factors which promoted cell renewal, while the decrease in mitotic activity associated with malnutrition may be explained, in part, by the decreased stimulation provided by the limited food intake, especially where anorexia is a feature of the illness.112
Acute Alveolar Injury: Experimental Models
Joan Gil in Models of Lung Disease, 2020
Assuming no large decrease in pool size or mitotic rate in other cell populations, the data indicate that endothelial mitoses increased sharply at 36 and 48 h, but we must remember that the numbers of endothelial mitoses and of 3H-labelled endothelial cells are expressed as percentages of all alveolar cell typesin mitosis or labelled and not as percent of total endothelial cells. Because of this it is not possible to conclude that the peak of mitotic activity in endothelial cells occurs at 2 days. A relatively greater increase in mitotic rate in one or more other cell types would lead to a decrease in mitotic index and labelling index in endothelial cells even if the mitotic rate in the endothelial population were increasing. In order to reach conclusions about change in mitotic rate in the endothelium or in any other cell population, mitotic counts or counts of cells incorporating [3H]thymidine must be expressed as percent of the cell type in question.
The Role of Insulin-like Growth Factor-Axis and Mitotic Index in South Indian Neonates with Small for Gestational Age
Published in Fetal and Pediatric Pathology, 2023
Nithya M. N., Krishnappa J., Sheela S. R., Venkateswarlu Raavi
Mitosis is an intrinsic property of a cell that contributes to the growth of the somatic cells. The mitotic index is the percentage of cells undergoing mitosis in a given cell population and it is a measure of cellular proliferation [16]. In our previous study, we observed that the mitotic index of lymphocytes from different blood groups (A, B, AB, and O) exposed to ionizing radiation showed a significant difference indicating a differential proliferation response among the blood types [16]. The mitosis in fetal cells contributes to the growth and development of the fetus and it depends on nutritional status, hormones, growth factors, and environmental factors. The studies on GH/IGF-axis components and SGA revealed that there are contrasting results that might depend on nutrition, environment, hormone levels, genetic makeup [2, 17]. Delineating the role of the IGF-axis and mitotic index in SGA may help improve management of SGA neonates. In the present study, we measured the levels of IGF1, IGF2, and IGFBP3 proteins, mitotic index in the cord blood, and the expression of IGFR1 and IGFR2 mRNA in the placenta to find if there any difference in these parameters between AGA and SGA neonates born to south Indian women.
Magnetic field direction differentially impacts the growth of different cell types
Published in Electromagnetic Biology and Medicine, 2018
Xiaofei Tian, Dongmei Wang, Meng Zha, Xingxing Yang, Xinmiao Ji, Lei Zhang, Xin Zhang
PC9 cells were plated on coverslips in 35-mm cell culture plates with or without magnetic field exposure. After 3 days, cells were washed once with PBS and fixed by precooled methanol (−20 °C) for 5 min. Then, the coverslips were washed with TBS-Tx (TBS supplemented with 0.1% Triton X-100) and blocked by AbDil-Tx [TBS-Tx with 2% (wt/vol) BSA and 0.5% sodium azide] at room temperature at least for 30 min. Coverslips were stained with anti-β-tubulin antibody (TransGen Biotech) at room temperature for 2 h, followed by fluorescently conjugated secondary antibodies (Thermo Fisher Scientific) at room temperature for 1 h. After washed with TBS-Tx, coverslips were mounted in anti-fade Prolong Gold mounting medium with DAPI (Invitrogen). Leica DMI4000B fluorescent microscope was used to get immunofluorescence images. Then, we used Adobe Photoshop software to count the numbers of cells in different cell cycle stages, including interphase, prophase, prometaphase, metaphase, anaphase and telophase. We also counted the numbers of cells with multipolar spindles. Mitotic index is the percentage of cells in mitosis.
Olfactory nerve schwannoma: how human anatomy and electron microscopy can help to solve an intriguing scientific puzzle
Published in Ultrastructural Pathology, 2022
Fabbri Vp, Valentina Papa, Tonon C, Agati R, Toni F, Zoli M, Mazzatenta D, Fioravanti A, Badaloni F, Cenacchi G, Foschini Mp, Asioli S
On histology, the lesion was mostly composed of compact spindle cells organized in whorls and fascicles with Verocay bodies (Figure 4a). Some areas were loose-textured and showed a myxoid appearance. The mitotic index was very low (<1 mitosis/50 HPF). On immunohistochemistry, the neoplastic cells showed strong and diffuse S-100 and SOX10 protein positivity (Figure 4b, 4c), whereas were negative for Epithelial Membrane Antigen (EMA) and Progesterone Receptor (PR). The expression of H3K27me3 was retained. CD57/Leu7 was negative (Figure 4d). Collagen IV immunostain evidenced the deposition of the basal lamina (Figure 5a). Neurofilament immunostaining showed scattered neuronal axons mainly located at the periphery of the lesion. The proliferative index (Ki-67) was 5%.