[DNA quantification and triploidy phenotype in the second and third trimesters of pregnancy]. / Quantification de l'A.D.N. et phénotype de triploïdie aux deuxième et troisième trimestres de grossesse.

Triploidy is often associated with early abortions, but may evolve during the second trimester taking a peculiar phenotype. The conditions of diagnosis or abortion do not always let the possibility of karyotyping. Thus, DNA quantification takes all its value. Twenty-three fetuses and placentas, ranging from 14 to 30 weeks of gestation with a phenotype of triploidy were analysed. Twelve cases were proved by karyotype. The DNA index studied in 6 of these was near 1.5, which confirmed the validity of the technique. Out of 11 phenotypes without karyotyping, DNA analysis identified 4 triploidies and a possible tetraploidy. So, a series of 16 cases could be collected, including 10 partial hydatidiform moles and 6 hypotrophic or normal fetuses and placentas.

Discrepancies of DNA content of various solid tumours before and after culture measured by image analysis. Comparison of cytogenetical data.

Parallel cytophotometric ploidy studies and cytogenetic analysis were performed on 15 various human solid tumours. The quantification of DNA by image analysis was carried out on cytological imprints of fresh tumours and on smears obtained after cell culture. The results obtained by both sets of calculations were compared with each other and with the cytogenetic results. 6 cases (40%) showed concordance between the 3 techniques. One case was aneuploid for both DNA image analysis measurements but the cytogenetic data showed only a diploid stem line. In 3 cases out of 15 (20%), smears DNA analysis and cytogenetic results were concordant: in 2 tumours, the culture step failed to preserve aneuploid stem lines that were present in the imprint analysis. In the third one, a minority tetraploid peak observed after culture was absent on the imprint slide. Concordance between imprints and cytogenetic data and discordance with smears' analysis was observed in 3 cases (20%). These 3 cases were diploid or near diploid but the DNA analysis on the smears after culture showed an aneuploid stem line in each case. The last 2 cases showed a total disagreement between the 3 techniques. By measuring the DNA content with an image analyser, the observer can ensure that only tumoral cells are taken into account. The present study revealed that cytogenetic data represent only about 60% of the population that is effectively present in the culture dish and that the cultured population represents only 47% of the population present on the fresh tumour imprint.

Non radioactive single-strand conformation polymorphism (SSCP) analysis of exon 11 of the CFTR gene using the Pharmacia PhastSystem.

The authors report here the use of the PhastSystem (Pharmacia) to perform the single strand conformation polymorphism analysis of polymerase chain reaction products of the exon 11 of the CFTR gene. It provides a rapid (2 hours) safe and reliable technique for the development of carrier testing for individuals or couples with a family history of cystic fibrosis.

Immunolocalization of matrix metallo-proteinases and their tissue inhibitor in human mammary pathology.

Matrix metallo-proteinases (MMPs) are a group of enzymes thought to be responsible for both normal connective tissue matrix remodelling and accelerated breakdown associated with tumor development. The distribution of 3 major matrix metallo-proteinases was studied in human mammary pathology: collagenase (MMP1) which degrades fibrillar interstitial collagens, a 72-kDa gelatinase (MMP2) which mainly degrades type IV collagen and denatured collagens, and stromelysin (MMP3) which has a wider range of action, degrading several matrix components including the core proteins of proteoglycans, laminin and non-helical regions of collagens. These MMPs and the MMP tissual inhibitor (TIMP1) were detected by immunohistochemistry in 30 benign and 79 malignant lesions of the breast. MMPs were detected in 1 fibroadenoma (collagenase) and 22 breast carcinomas: collagenase (9 cases), stromelysin (12 cases) and gelatinase (16 cases) with a limited distribution. Tumor cells were preferentially labelled and the localization of gelatinase and stromelysin at the periphery of some non-invasive and well-differentiated clusters supports the role of these enzymes in the breakdown of basement membranes. Only a few stromal cells (fibroblasts) were found to be immunopositive. In contrast, TIMP1 was more frequently detected, and was found in 7 benign lesions and 55 carcinomas out of 79. It was mainly localized at the periphery of the endothelial cells but was occasionally detected in cancer cells and fibroblasts.

Detection by in situ hybridization of messenger RNAs of collagen types I and IV in murine mammary cancer.

Ten breast carcinomas developing in C3H/Bi female mice were studied by an in situ hybridization technique using cDNA probes encoding alpha-I chains of collagens of types I and IV. The results obtained are compared to histochemical data on antibodies to collagens of types I and IV and ultrastructural observations on these tumors. Immunohistochemistry has revealed the presence of type-IV collagen in basement membranes lining intraductal and well-differentiated cancer nests. Type-I collagen was detected in the stroma surrounding these cells. There was no cellular labelling when these antisera were used. In situ hybridization has shown that type-IV collagen mRNA is detected in non-invasive intraductal and well-differentiated tumor cells and in endothelial cells in the stroma. Good correlation between detection of type-IV collagen lining these cells and evidence of mRNA by in situ hybridization was thus observed. Invasive cancer cells did not express hybridization grains with the type-IV collagen probe. Type-I collagen mRNA was visualized in stromal cells, probably fibroblasts and myofibroblasts as shown by electron microscopy. The most active cells were localized close to non-invasive areas. Our data indicate persistent in-vivo biosynthesis of type-IV collagen by some cancer cells that produce their own limitative environment; they suggest that type-IV collagen is not produced by invasive tumor cells and that stromal cells lining the non-invasive regions have a peculiar behavior.