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Neuro-oncology May 2015
Topics: Biomarkers, Tumor; Female; Histones; Humans; Male; Meningioma; Mitosis; Mitotic Index
PubMed: 25813470
DOI: 10.1093/neuonc/nov047 -
Mutation Research Jul 1998Pregnant females appear to have an increased chromosomal sensitivity to gamma-irradiation. This hypersensitivity was found to parallel the increase of gestation hormone...
Pregnant females appear to have an increased chromosomal sensitivity to gamma-irradiation. This hypersensitivity was found to parallel the increase of gestation hormone amounts [M. Ricoul, L. Sabatier, B. Dutrillaux, Increased chromosome radiosensitivity during pregnancy, Mutat. Res. 374(1997) 73-78]. An in vitro experiment was developed to study the effect of progesterone. We performed irradiations of whole blood from normal human donors and chromosome were analysed in first generation metaphases. By comparison to untreated controls, all cultures in which progesterone was added around the 24th h of culture exhibited an increased frequency of chromosome rearrangements, principally dicentrics and rings, which confirms the role of progesterone in the results of in vivo studies. BrdU incorporation studies suggested that progesterone was particularly efficient just before the entry into S-phase, which corresponds to the G1/S transition period. Cultures with an increased frequency of chromosome breakage had a slightly higher mitotic index than controls. It is suggested that progesterone may stimulate DNA repair in cells which reached the end of G1-phase with unrepaired breaks. This would allow the cells to enter the S-phase and survive, although some illegitimate repair leads to chromosome rearrangements, visible at the following metaphase.
Topics: Blood Cells; Chromosome Breakage; Female; G1 Phase; Humans; In Vitro Techniques; Microscopy, Fluorescence; Mitotic Index; Mutation; Pregnancy; Progesterone; Radiation Tolerance; S Phase
PubMed: 9726018
DOI: 10.1016/s0027-5107(98)00078-5 -
Histopathology Jul 2001Mitotic counting in surgical pathology: sampling bias, heterogeneity and statistical uncertainty Although several articles on the methodological aspects of mitotic... (Review)
Review
Mitotic counting in surgical pathology: sampling bias, heterogeneity and statistical uncertainty Although several articles on the methodological aspects of mitotic counting have been published, the effects of macroscopic sampling and tumour heterogeneity have not been discussed in any detail. In this review the essential elements for a standardized mitotic counting protocol are described, including microscopic calibration, specific morphological criteria, macroscopic selection, counting procedure, effect of biological variation, threshold, and the setting of an area of uncertainty ('grey area'). We propose that the use of a standard area for mitotic quantification and of a grey area in mitotic counting protocols will facilitate the application of mitotic counting in diagnostic and prognostic pathology.
Topics: Data Interpretation, Statistical; Genetic Heterogeneity; Humans; Mitosis; Mitotic Index; Neoplasms; Pathology, Surgical; Selection Bias
PubMed: 11454038
DOI: 10.1046/j.1365-2559.2001.01187.x -
Breast Cancer Research and Treatment May 2009Independent studies have shown that in node negative breast cancer patients less than 71 years, the proliferation marker mitotic activity index (MAI) is the strongest,... (Review)
Review
Independent studies have shown that in node negative breast cancer patients less than 71 years, the proliferation marker mitotic activity index (MAI) is the strongest, most well reproducible prognosticator and chemotherapy success predictor. The MAI overshadows the prognostic value of tubule formation, nuclear atypia and thereby grade. An often used crude mitotic impression is much less prognostic than the MAI; strict adherence to the MAI protocol is therefore important. The prognostic value of the MAI is age dependent: although patients with a MAI > or = 10 always have a poor prognosis irrespective of age, a low MAI (<10) loses its favourable prognostic association in women >70 years. PPH3 counts are prognostically stronger than the MAI, and markers such as Cyclin-B and E2FR are promising, but must be validated. Compared with commercial prognostic gene expression signatures, the MAI is at least as strong prognostically, has far fewer false positive results and as such should be included as an independent feature in any node negative breast cancer pathology report.
Topics: Age Factors; Aged; Biomarkers, Tumor; Breast Neoplasms; Cell Proliferation; Female; Humans; Middle Aged; Mitotic Index; Prognosis; Tissue Fixation
PubMed: 18665447
DOI: 10.1007/s10549-008-0126-y -
Veterinary Pathology Mar 2021Counting mitotic figures (MF) in hematoxylin and eosin-stained histologic sections is an integral part of the diagnostic pathologist's tumor evaluation. The mitotic...
Counting mitotic figures (MF) in hematoxylin and eosin-stained histologic sections is an integral part of the diagnostic pathologist's tumor evaluation. The mitotic count (MC) is used alone or as part of a grading scheme for assessment of prognosis and clinical decisions. Determining MCs is subjective, somewhat laborious, and has interobserver variation. Proposals for standardizing this parameter in the veterinary field are limited to terminology (use of the term MC) and area (MC is counted in an area measuring 2.37 mm). Digital imaging techniques are now commonplace and widely used among veterinary pathologists, and field of view area can be easily calculated with digital imaging software. In addition to standardizing the methods of counting MF, the morphologic characteristics of MF and distinguishing atypical mitotic figures (AMF) versus mitotic-like figures (MLF) need to be defined. This article provides morphologic criteria for MF identification and for distinguishing normal phases of MF from AMF and MLF. Pertinent features of digital microscopy and application of computational pathology (CPATH) methods are discussed. Correct identification of MF will improve MC consistency, reproducibility, and accuracy obtained from manual (glass slide or whole-slide imaging) and CPATH approaches.
Topics: Animals; Eosine Yellowish-(YS); Hematoxylin; Mitotic Index; Reproducibility of Results; Software
PubMed: 33371818
DOI: 10.1177/0300985820980049 -
Pathology, Research and Practice 1980"The problem of amitosis" (Bucher, 1971) has historical, theoretical, formal, and methodological aspects. Most cases of amitosis described during the past 125 years have...
"The problem of amitosis" (Bucher, 1971) has historical, theoretical, formal, and methodological aspects. Most cases of amitosis described during the past 125 years have proved to be misinterpretations of incomplete mitoses. Binucleate cells and occasionally dumbbell-shaped restitution nuclei are formed as the result of mitotic inhibitions, which increases with tissue differentiation. Until recently, binucleate cells in the myocardium have been interpreted as products of amitotic nuclear divisions, since mitoses are not found in human myocardium. However, mitoses are found in postnatal pig hearts fixed immediately after death. The mitotic index declines from 2.2% at day ten to 0.3% at day thirty during postnatal life. Delayed fixation yields degenerated prophase and telophase nuclei only. Thus the formation of binucleate myocardial cells and nuclear rows is the result of mitoses with impeded cellular divisions. To call these findings examples of amitosis is a misinterpretation.
Topics: Animals; Cell Differentiation; Humans; Mitosis; Mitotic Index; Myocardium; Swine
PubMed: 7433237
DOI: 10.1016/S0344-0338(80)80059-8 -
Pathology International Dec 2022
Topics: Humans; Metaphase; Mitotic Index; Mitosis; Mucous Membrane; Colchicine
PubMed: 36205481
DOI: 10.1111/pin.13276 -
Laboratory Investigation; a Journal of... Nov 2019As part of routine histological grading, for every invasive breast cancer the mitotic count is assessed by counting mitoses in the (visually selected) region with the...
As part of routine histological grading, for every invasive breast cancer the mitotic count is assessed by counting mitoses in the (visually selected) region with the highest proliferative activity. Because this procedure is prone to subjectivity, the present study compares visual mitotic counting with deep learning based automated mitotic counting and fully automated hotspot selection. Two cohorts were used in this study. Cohort A comprised 90 prospectively included tumors which were selected based on the mitotic frequency scores given during routine glass slide diagnostics. This pathologist additionally assessed the mitotic count in these tumors in whole slide images (WSI) within a preselected hotspot. A second observer performed the same procedures on this cohort. The preselected hotspot was generated by a convolutional neural network (CNN) trained to detect all mitotic figures in digitized hematoxylin and eosin (H&E) sections. The second cohort comprised a multicenter, retrospective TNBC cohort (nā=ā298), of which the mitotic count was assessed by three independent observers on glass slides. The same CNN was applied on this cohort and the absolute number of mitotic figures in the hotspot was compared to the averaged mitotic count of the observers. Baseline interobserver agreement for glass slide assessment in cohort A was good (kappa 0.689; 95% CI 0.580-0.799). Using the CNN generated hotspot in WSI, the agreement score increased to 0.814 (95% CI 0.719-0.909). Automated counting by the CNN in comparison with observers counting in the predefined hotspot region yielded an average kappa of 0.724. We conclude that manual mitotic counting is not affected by assessment modality (glass slides, WSI) and that counting mitotic figures in WSI is feasible. Using a predefined hotspot area considerably improves reproducibility. Also, fully automated assessment of mitotic score appears to be feasible without introducing additional bias or variability.
Topics: Adult; Aged; Breast Neoplasms; Cohort Studies; Deep Learning; Diagnosis, Computer-Assisted; Female; Humans; Middle Aged; Mitotic Index; Netherlands; Neural Networks, Computer; Observer Variation; Prospective Studies; Reproducibility of Results; Retrospective Studies
PubMed: 31222166
DOI: 10.1038/s41374-019-0275-0 -
Medical and Pediatric Oncology 1976The effects of various concentrations of hydroxyurea (HU) on a human lymphoid cell line in exponential growth phase have been studied using a combination of methods,...
The effects of various concentrations of hydroxyurea (HU) on a human lymphoid cell line in exponential growth phase have been studied using a combination of methods, including determination of the total and viable cell counts; the cells relative DNA content, measured in a flow microfluorimeter after staining with a fluorescent Feulgen technique; the mitotic index; and the percentage of cells incorporating thymidine-3H (TdR-3H) during brief and continuous exposure to the isotope both in the presence and absence of colcemid. A significant redistribution of the cells in the various phases of the cell cycle occurred during the first 24 hr of continuous treatment with 10(-3) M and 10(-2) M HU as follows: (1) division of cells in G2; (2) depletion of mid and late S phase cells due to early cell death; (3) movement of most G1 cells at a normal rate into early S phase where they accumulate; and (4) arrest of the remaining cells in G1, which represented the surviving population after treatment for 96 hr or longer. After removal of the drug, the cell fraction blocked in early S phase progressed semisynchronously through S, but many of the cells were unable to complete division. Their capacity to recover depended on the drug concentration and duration of exposure, but in general the cellular injury caused by HU was more reversible than that caused by "equivalent" concentrations of arabinosylcytosine.
Topics: Cell Count; Cell Line; Cell Survival; DNA Replication; Humans; Hydroxyurea; Leukemia, Myeloid; Mitosis; Mitotic Index; Thymidine; Trypan Blue
PubMed: 1064742
DOI: 10.1002/mpo.2950020105 -
Current Topics in Pathology. Ergebnisse... 1996
Review
Topics: Biomarkers, Tumor; Cell Division; Humans; Ki-67 Antigen; Mitotic Index; Pathology, Oral; Proliferating Cell Nuclear Antigen
PubMed: 8791751
DOI: 10.1007/978-3-642-80169-3_5