Cytogenetic analysis of primary cell cultures from human atherosclerotic fibrous plaques revealed clonal chromosome abnormalities in 13 of the 18 cases studied. Loss of the Y chromosome and del(13)(q14) were present as single clonal abnormalities in eight cases; in five cases separate clones were found involving loss of the Y and a XXY karyotype, trisomy 10 and 18, loss of the Y and trisomy 7. A variety of single numerical and structural abnormalities were present in all but two of the 18 cases. Immunocytochemical studies were performed on cells from the same cultures used for cytogenetic analysis using monoclonal antibodies to human leucocyte common antigen, to human vimentin and to muscle actin. The immunoreactivity was positive for actin in 70-80% of the cells; 100% of the cells were positive for vimentin and all cells were ALC negative. These results indicated that the chromosomal abnormalities are present in the smooth muscle cells of the plaque. The hypothesis is proposed that the proliferation leading to the atherosclerotic lesion may primarily represent a hyperplastic response to mechanical and biological injuries and that this reactive proliferation is, in turn, associated with a tendency to chromosome instability.

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Trisomy 7, trisomy 10 and loss of the Y chromosome have been found by some authors in presumptive normal parts of human kidneys. We describe cytogenetic findings in short-term cultures from 58 biopsies obtained from non-neoplastic and neoplastic (renal cell carcinoma, RCC) tissues from the same kidney, the same types of tissues from independent kidneys, and tissue from kidneys without neoplasia. The results indicate the following. Non-neoplastic tissue from kidneys involved in RCC have (in mosaics) trisomies 5, 7, 10, 18 and loss of the Y as non-random clonal changes. They are not the result of local metastasis but are also found in kidneys with non-tumoral chronic pathologies and should thus not be considered specific for RCC. They are neither culturing artefacts nor a general phenomenon found in cultured normal solid tissues, but are acquired abnormalities, possibly related to various reactive cellular states in the tissues that are histologically normal.

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Objectives To establish the positive predictive values (PPV) of cfDNA testing based on data from a nationwide survey of independent clinical cytogenetics laboratories. Methods Prenatal diagnostic test results obtained by Italian laboratories between 2013 and March 2020 were compiled for women with positive non‐invasive prenatal tests (NIPT), without an NIPT result, and cases where there was sex discordancy between the NIPT and ultrasound. PPV and other summary data were reviewed. Results Diagnostic test results were collected for 1327 women with a positive NIPT. The highest PPVs were for Trisomy (T) 21 (624/671, 93%) and XYY (26/27, 96.3%), while rare autosomal trisomies (9/47, 19.1%) and recurrent microdeletions (8/55, 14.5%) had the lowest PPVs. PPVs for T21, T18, and T13 were significantly higher when diagnostic confirmation was carried out on chorionic villi (97.5%) compared to amniotic fluid (89.5%) (p < 0.001). In 19/139 (13.9%), of no result cases, a cytogenetic abnormality was detected. Follow‐up genetic testing provided explanations for 3/6 cases with a fetal sex discordancy between NIPT and ultrasound. Conclusions NIPT PPVs differ across the conditions screened and the tissues studied in diagnostic testing. This variability, issues associated with fetal sex discordancy, and no results, illustrate the importance of pre‐ and post‐test counselling.