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M Longy

Publications and source records attributed to M Longy.

At least 55 records · Page 3Linked to original sources
PubMed1995

Allelic imbalance study of 16q in human primary breast carcinomas using microsatellite markers.

The high incidence of allelic imbalance on the long arm of chromosome 16 in breast cancer suggests its involvement in the development and progression of the tumor. Several loss of heterozygosity (LOH) studies have led to the assignment of commonly deleted regions on 16q where tumor suppressor genes may be located. The most recurrent LOH regions have been 16q22.1 and 16q22.4-qter. The aim of this study was to gain further insight into the occurrence of one or multiple "smallest regions of overlap" on 16q in a new series of breast carcinomas. Hence, a detailed allelic imbalance map was constructed for 46 sporadic breast carcinomas, using 11 polymorphic microsatellite markers located on chromosome 16. Allelic imbalance of one or more markers on 16q was shown by 30 of the 46 tumors (65%). Among these 30 carcinomas, LOH on the long arm of chromosome 16 was detected at all informative loci in 19 (41%); 13 of them showed allelic imbalance on the long but not on the short arm, with the occurrence of variable "breakpoints" in the pericentromeric region. The partial allelic imbalance in 11 tumors involved either the 16q22.1-qter LOH region or interstitial LOH regions. A commonly deleted region was found between D16S421 and D16S289 on 16q22.1 in 29 of the 30 tumors. The present data argue in favor of an important involvement of a tumor suppressor gene mapping to 16q22.1 in the genesis or progression of breast cancer.

Adult↗
PubMed1993

FGFRI and PLAT genes and DNA amplification at 8p12 in breast and ovarian cancers.

Several chromosomal regions are found to be consistently amplified in human breast cancers. For two of these regions, 8p12 and 10q26, we previously reported the amplification of genes encoding FGF receptors, FGFRI/FLG and FGFR2/BEK, in about 12% of breast tumors. The PLAT gene, encoding the tissue-type plasminogen activator, is also located close to or within the 8p12 region. In the present study, we show that both FGFRI and PLAT can be amplified in breast as well as ovarian carcinomas. FGFRI amplification was detected in 14.5% of breast and 7.8% of ovarian tumors, whereas PLAT was found to be amplified in 15.6% and 19.4% of the tumors, respectively. Each gene could be amplified independently of the other. These data raised the question of which gene is selected for amplification at 8p12. In most cases, the levels of expression of FGFRI and PLAT in breast tumors were comparable to their level of expression in normal mammary tissue. However, FGFRI was expressed above the normal level in a certain number of cases. This gene could be a good candidate as "driver" of the 8p12 amplification, but it cannot account for all complex molecular events taking place in this region.

Breast Neoplasms↗
PubMed1993

Chromosome analysis of adenomatous polyps of the colon: possible existence of two differently evolving cytogenetic groups.

A chromosomal study of 42 colonic adenomatous polyps was performed using a technique of direct chromosome analysis derived from the prenatal procedure for diagnosing chromosomal alterations from chorionic villi sampling. Abnormal karyotypes were found in 22 cases. Trisomy 7, the most frequently found alteration, was found in 13 cases, followed by trisomy 13 (nine cases). Monosomy 18 was observed in two cases; in one of these, that of a polyp which had degenerated into an intra-mucosal adenocarcinoma, it was associated with 17p monosomy. Interestingly, these two types of alterations (trisomy 7 versus 18 and 17p monosomy) were not found together in the same lesion. This suggests that there could be two distinct chromosomal behaviors which might be related to the two cytogenetic groups described for colorectal adenocarcinoma. However, the respective frequencies of such cytogenetic groups varied inversely between adenomas and adenocarcinomas, thus suggesting that they evolve differently.

Adult↗
PubMed1991

[Evaluation of the risks of transabdominal chorionic villus sampling. 600 cases].

The authors report their experience with fine needle chorionic villus sampling carried out transabdominally. Six hundred antenatal karyotype diagnoses were made using this method. The indications were: maternal age: 509 (85%), previous chromosomal abnormalities: 57 (9.5%), parental chromosomal abnormalities: 19 (3%), X chromosome linked diseases: 9 (1.5%), others: 6 (1%). The patients were divided into two groups according as to whether the test was carried out before or after 12 weeks of amenorrhea (Group 1 and Group 2). Each group was divided into two sub-groups according to whether the amniotic membranes were broken or not. The test was carried out using a 20 gauge needle under ultrasound control with a to-and-fro movement using continuous aspiration. The success rate was 98.4%. Minor complications were rare. Contractions 9 (1.5%), spotting 4 (0.6%), small haematomas 13 (2.1%), loss of amniotic fluid 4 (0.6%). The level of unintentional abortions depended on the duration of the pregnancy and whether the amniotic cavity or not was entered. In group 1 (before or at 12 weak amenorrhea) there were 2 abortions out of 124 cases (1.6%) and if the needle entered the amniotic cavity 10 out of 57 cases (17.5%). In group 2 (after 12 weeks of amenorrhea) there was no ill effect from going into the amniotic cavity to the rest of the pregnancy. The abortion rates was 6 out of 419 (1.43%). There were no false positive or negative results.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1990

Chromosomal analysis of colonic adenomatous polyps.

Chromosomal analysis of 25 colonic adenomatous polyps was performed by a direct method similar to that used in prenatal diagnosis of chromosomal aberration on chorionic villi. Fourteen lesions showed an abnormal karyotype. Two changes were recurrent: trisomy 7 (observed in eight cases) and trisomy 13 (observed in seven cases). No monosomy of the short arm of chromosome 17 was observed even at the level of two polyps with in situ carcinoma lesions.

Adenocarcinoma↗
PubMed1990

Risks of transabdominal chorionic villus sampling before the 12th week of amenorrhea.

The authors report on a series of 210 chorion villus sampling diagnoses made with a needle by the transabdominal route. The rate of fetal loss was 4.2 per cent. Placental localization was important: fetal losses were 8 per cent when the placenta was strictly posterior (transamniotic route), whereas it was only 1.6 per cent when it was not posterior. Moreover, all fetal losses occurred (apart from one at 12.5 weeks of amenorrhea) before the 12th week of amenorrhea. The authors suggest that choriocentesis by the transabdominal route should not be performed before the 12th week of amenorrhea, and that the amniotic membrane should not be disturbed before the 13th week of amenorrhea.

Abdomen↗
PubMed1989

Direct chromosome analysis in the second and third trimesters by placental biopsy in 30 pregnancies.

Direct chromosome analysis was performed on placental villi obtained by ultrasound-guided transabdominal needle aspiration in 30 women at between 23 and 37 weeks gestation. Placental biopsy is simple in the presence of severe oligohydramnios where fetal blood sampling is usually more difficult. Direct karyotyping of placental villi is more rapid than chromosomal analysis from fetal blood and from amniotic fluid. Two chromosomal anomalies were discovered: one trisomy 18 and one 6p+. Villus sampling failed in one woman and two samples obtained at 36 and 37 weeks gestation could not be karyotyped. The procedure did not affect the outcome of the pregnancy.

Adult↗
PubMed1988

[Basal decidual hematoma persisting after biopsy of the trophoblast].

A late complication of CVS by forceps biopsy is reported. It is the immediate formation of a retroplacental hematoma on the location of the sampling which is revealed by a bleeding across the cervix. During all the pregnancy retroplacental hematoma and bleeding will persist until the delivery by cesarean section at 31 weeks of amenorrhea. Such a late complication has not been reported in the literature.

Adult↗
PubMed1988

[Placentocentesis, a new technic in the prenatal diagnosis of chromosome aberrations in the 3d trimester. A preliminary study apropos of 5 cases].

The authors report 5 cases in which placentocentesis was used for late antenatal diagnosis between the 25th and 34th week of amenorrhoea. As the placenta was anteriorly placed, samples were obtained by aspiration through the abdominal route under ultrasound control. The fetal karyotype could be determined in 2 days using a direct method. It showed normal chromosome pictures in all 5 cases. There was no complication in any of these cases following the procedure.

Adult↗
PubMed1988

[Improvement of a chromosomal technic for trophoblast biopsy. Apropos of 200 cases].

The authors report their experience of 200 cases of prenatal diagnosis by biopsy of chorionic villi. Because they could not consistently obtain good quality chromosome banding, they propose a modification of the conventional direct method. The addition of methanol in sufficient proportions to the nuclear suspension makes it possible to obtain spontaneous spreading on slides heated to 65 degrees C and eliminates the problems of mechanical spreading.

Adult↗