Biomedical subjects

B Andréo

Publications and source records attributed to B Andréo.

At least 19 recordsLinked to original sources

PubMed2006

Multicolor PRINS and multicolor PNA.

Both PRimed IN Situ (PRINS) and Peptide Nucleic Acid (PNA) technologies have emerged as research techniques, but they have quickly evolved to applications in biological diagnosis assays. The two procedures now constitute efficient alternatives to the conventional fluorescence in situ hybridization (FISH) procedure for in situ chromosome identification and aneuploidy detection. They present several advantages (specificity, speed, discriminating ability) that make them very attractive for a number of cytogenetic purposes. Multicolor PRINS and PNA protocols have been described for the specific identification of human chromosomes. Various applications have already been developed in human genetics and new adaptations are ongoing.

Chromosome Mapping↗

PubMed2005

Sperm segregation analysis of a (13;22) Robertsonian translocation carrier by FISH: a comparison of locus-specific probe and whole chromosome painting.

BACKGROUND: The t(13;22) Robertsonian translocation constitutes a rare form of rearrangement between acrocentric human chromosomes. Most of the meiotic segregation studies of human Robertsonian translocations have been performed on common t(13;14) and t(14;21) translocations. Analysis of the chromosomal constitution in sperm of Robertsonian translocation carriers is of great interest for assessing the risk of unbalanced forms and adapting genetic counselling. In the present study, we present the first meiotic segregation study of a t(13;22) Robertsonian translocation in human sperm. METHODS: A total of 11 787 sperm nuclei were scored using two distinct FISH labelling techniques, i.e. the locus-specific probes (LSI) method and the whole chromosome painting (WCP) technique. RESULTS: The frequency of normal or balanced sperm resulting from alternate meiotic segregation was 86%. Incidences of unbalanced complements resulting from adjacent segregation modes were 12.79% and 14.36% in LSI and WCP assays, respectively. No significant excess of nullisomy or disomy for the affected chromosomes was observed. CONCLUSIONS: Similar results in segregation were obtained with the two techniques, demonstrating the efficiency of the two strategies for the direct segregation analysis of Roberstsonian translocations. The results obtained indicated a moderate meiotic production of imbalance. This study shows that the rare Robertsonian translocation (13;22) displays a similar distribution of balanced and unbalanced sperm patterns as the common Robertsonian translocations previously studied. This suggests that the behaviour of acrocentric chromosomes was similar in all cases of centric fusion.

Adult↗

PubMed2005

[The cytogenetics of human oocytes: 40 years of progress].

Chromosomal abnormalities account for the majority of pre- and post- implantation embryo wastage in humans. Most of these abnormalities result from maternal meiotic errors, which preferentially occur during the first meiotic division. Consequently, the cytogenetic analysis of human oocytes has then been considered as a highly valuable source of data for the investigation of both the occurrence and the origin of chromosomal abnormalities in human. During the last 4 decades, the cytogenetic analysis of human oocytes has never stopped progressing, according to the advents of new technologies. Both karyotyping and molecular cytogenetic studies have been reported to date, providing a large body of data on the incidence and the distribution of chromosomal abnormalities in human female gametes. However, these studies display a great variability in results, which may be essentially attributable to the limitations of these techniques when applied to human oocytes. The most relevant analysis have led to the estimate that 15-20% of human oocytes present chromosome abnormalities, and they have emphasized the implication of both whole chromosome non-disjunction and chromatid separation in the occurrence of aneuploidy in human oocytes. The effect of advanced maternal age on the incidence of aneuploidy in human oocytes has also been clearly evidenced by recent reports based on large sample of oocytes or polar bodies.

Cell Division↗

PubMed2004

The peptide nucleic acids as probes for chromosomal analysis: application to human oocytes, polar bodies and preimplantation embryos.

Peptide nucleic acids (PNA) are synthetic DNA mimics based on an uncharged polyamide backbone, which hybridize with complementary DNA with high affinity and specificity. PNA have recently become recognized as efficient tools for in situ chromosomal identification. In the present study, this new approach has been tried on isolated human oocytes, polar bodies and blastomeres. Using centromeric PNA probes specific for chromosomes 1, 4, 9, 16, X and Y, we tested multicolour labelling PNA reaction on 27 oocytes and 23 blastomeres. Sequential PNA hybridization was performed on five oocytes and combined PNA and fluorescence in situ hybridization (FISH) reactions on two oocytes. Both the rates and the types of abnormalities observed are in agreement with results from previous FISH studies. This preliminary study indicates that PNA probes allow a reliable chromosomal analysis in isolated human oocytes and blastomeres and consequently might provide an interesting adjunct to FISH for diagnostic analysis.

Blastocyst↗

PubMed2003

Sequential multiple probe fluorescence in-situ hybridization analysis of human oocytes and polar bodies by combining centromeric labelling and whole chromosome painting.

The incidence of chromosomal aneuploidy was analysed in 104 unfertilized human oocytes and 56 first polar bodies using a double-label fluorescence in-situ hybridization (FISH) procedure. Combinations of centromeric (or locus-specific) DNA probes and whole chromosome painting probes for chromosomes 9, 13, 16, 18, 21 and X were applied on oocyte preparations, in a sequential FISH protocol. This combined approach allowed a precise in-situ identification of both chromosomes and free chromatids, and consequently a reliable analysis of chromosomal segregation errors. Of the 104 analysed oocytes, 84 (80.7%) displayed a normal chromosome constitution. Three cases of chromosome non-disjunction (2.8%) were found, whereas seven oocytes (6.7%) presented extra single chromatids. In addition, 12 oocytes (11.5%) showed balanced pre-division of one pair of sister chromatids. Although this phenomenon was not classified as aneuploidy, it could lead to aneuploidy at anaphase II. Abnormalities were observed in all the targetted chromosomes. The present data confirm that both whole chromosome non-disjunction and premature chromatid separation constitute the two major mechanisms of aneuploidy in human female meiosis.

Centromere↗

PubMed2002

Ultra-rapid multicolor PRINS protocol for chromosome detection in human sperm.

We report a new multicolor PRINS procedure for chromosome identification on human sperm. Based on the direct in-situ mixing of the colors of the fluorochromes (FITC, TRITC, Cascade Blue) incorporated in sequential PRINS reactions, this method facilitates rapid distinct labeling of 3 or 4 chromosomes. Each PRINS reaction consists of a unique 4 minute step for annealing and elongation. The method was successfully tested on lymphocytes and spermatozoa. Estimates of disomy were performed for chromosomes 7, 9 and 16 on sperm samples from 2 healthy donors. There was no significant difference between the disomy rates obtained with the conventional two-color PRINS technique and this new three-color procedure. By simplifying the multicolor PRINS protocol, this new protocol should facilitate the use and adaptation of PRINS to various cytogenetic applications.

Chromosomes, Human, Pair 16↗

PubMed2001

Study of the occurrence of interchromosomal effect in spermatozoa of chromosomal rearrangement carriers by fluorescence in-situ hybridization and primed in-situ labelling techniques.

The possibility that a chromosomal rearrangement might disturb the meiotic behaviour of chromosomes not involved in the rearrangement and favour non-disjunction is a controversial issue in human cytogenetics. Using two-colour fluorescence in-situ hybridization and primed in-situ labelling techniques, we have investigated the segregation pattern of 10 chromosomes (chromosomes 1, 4, 9, 13, 15, 16, 20, 21, X and Y) in spermatozoa from nine carriers of balanced structural rearrangements and three normal men. The patients were divided into two groups according to their semen parameters. In rearrangement carriers and normal subjects, sex chromosomes and chromosome 21 displayed a higher rate of disomy than the other chromosomes. No evidence for the occurrence of interchromosomal effect was found in the spermatozoa of fertile rearrangement carriers, but significant variations were observed for all chromosomes tested in the group of infertile translocation carriers, suggesting a direct correlation between poor quality spermatozoa and increased aneuploidy rate in this group. In fertile carriers of chromosomal rearrangements, the occurrence of non-disjunction of chromosomes not involved in the rearrangement might therefore be considered as fortuitous, whereas in infertile carriers, the risk for interchromosomal effect appears to be real and should be taken into consideration in the genetic counselling of infertile couples with a male partner carrying a chromosomal rearrangement.

Adult↗

PubMed1999

Interphasic analysis of aneuploidy in cancer cell lines using primed in situ labeling.

The primed in situ (PRINS) labeling technique has been adapted to chromosomal screening of interphasic tumoral cells. A panel of ten chromosome-specific alpha-satellite DNA primers was used to evaluate numerical chromosome abnormalities in two colon cancer cell lines (Caco-2 and HT-29) and in three of their subpopulations (PF11, TC7, and HT29-MTX). In each cell line, the copy number distribution for different chromosomes showed different patterns. The observation of significant variations in the chromosome constitutions between subpopulations derived from the same original tumor suggests the common occurrence of chromosome copy number heterogeneity in tumoral cell lines. This study demonstrates that the PRINS procedure offers a simple and reliable method for in situ chromosomal screening, which could be efficiently used for karyotypic analysis of tumoral cells.

Aneuploidy↗

PubMed1997

Primed in situ (PRINS) labelling with Alu and satellite primers for rapid characterization of human chromosomes in hybrid cell lines.

The primed in situ (PRINS) labelling method was developed as an alternative to classical cytogenetics and fluorescence in situ hybridization (FISH) for the characterization of interspecific somatic hybrids. Full karyotypes were performed by PRINS using Alu-specific primers to generate the painting of all human material associated with R-like banding. The representativity of individual human chromosomes was established using primers specific for discriminent alpha-satellite DNA sequences providing specific signals on the centromeres of the targeted chromosomes and corresponding spots in interphase nuclei. Using this methodology, a somatic hybrid clone was shown to be monochromosomal for the der(11) from a t(11;22) patient.

Animals↗

PubMed1997

Incidence of chromosome 1 disomy in human sperm estimated by the primed in situ (PRINS) labeling technique.

The primed in situ (PRINS) labeling technique was used to determine the rate of disomy of chromosomes 1 and 16 in sperm of two normal subjects. Two different but specific primers (alpha-satellite and satellite II) for chromosome 1 were used in parallel experiments to test the efficiency of PRINS labeling in sperm nuclei. A minimum of 10,000 sperm nuclei per chromosome primer was analyzed, leading to a total number of 41,651 scored spermatozoa. Similar rates of chromosome 1 disomy (mean values, 0.18% and 0.20%) were found in both donors when the alpha-satellite and satellite II primers were used, demonstrating the reliability of PRINS labeling on sperm nuclei. For chromosome 16, the disomy rate among the two donors ranged from 0.20% to 0.24%. This study confirms that PRINS provides a rapid and efficient method for in situ chromosomal screening of sperm nuclei.

Adult↗

PubMed1997

Cytogenetic analysis of meiotic segregation in sperm from two males heterozygous for reciprocal translocations using PRINS and humster techniques.

The meiotic segregation patterns of 2 reciprocal translocations t(7;9)(q33;p21) and t(7;18)(q35;q11) were analyzed in sperm of 2 heterozygote carriers. Both sperm karyotyping and in situ PRINS labeling of sperm nuclei were performed on a sperm sample from each subject. Using the humster technique, 54 and 72 sperm chromosome complements were successfully analyzed for the t(7;9) and the t(7;18) respectively. The frequencies of alternate, adjacent 1, adjacent 2 and 3:1 segregations were 44.44%, 37.04%, 12.96% and 5.56% for the t(7;9) and 33.33%, 43.05%, 19.45% and 4.17% for the t(7;18). The PRINS procedure allowed the rapid screening of large samples of spermatozoa. However, alternate and adjacent 1 segregants were not discriminated because of the generation of centromeric signals. The segregation pattern was determined on 10,658 spermatozoa for the t(7;9) and 10,462 for the t(7;18). The distributions of segregants were similar to those obtained by sperm karyotyping. These data were pooled with results from 37 reciprocal translocations previously studied by sperm karyotyping and 6 recently investigated by FISH. The analysis of these compiled data demonstrates the particularity of the production of imbalances in male gametes; independent of the predisposition for a type of imbalance at term, there is a preferential production of adjacent 1 imbalance in sperm.

Adult↗

PubMed1996

Aneuploidy detection in human sperm nuclei using PRINS technique.

Rapid and specific identification of chromosomes can be attained in situ using the PRimed IN Situ (PRINS) labelling technique. We have adapted this technique to mature human sperm in combination with a protocol for simultaneous decondensation and denaturation of sperm nuclei. This strategy allowed us to obtain double labelling of human spermatozoa in a < 2-hr reaction. In the present study, we report the estimates of disomy for chromosomes 3, 7, 10, 11, and 17 on 64,642 spermatozoa from 2 normal males. The incidences of disomy ranged from 0.28-0.34%. There were no significant interindividual or interchromosomal differences in disomy rates.

Adult↗

PubMed1996

Direct detection of disomy in human sperm by the PRINS technique.

We report the use of the PRimedIN Situ (PRINS) labelling technique for the direct estimation of disomy rates for various chromosomes in human sperm. The PRINS technique provides a rapid and reliable method for chromosome screening since specific labelling may be obtained in less than 2 h. In the present study, the disomy rates of chromosomes 2, 5, 9, 12 and 18 were investigated. The incidences of disomy are similar for all these chromosomes, ranging from 0.27% to 0.33%. These findings suggest an equal distribution of aneuploidies among autosomes in human sperm.

Aneuploidy↗

PubMed1996

Rapid chromosome detection in human gametes, zygotes, and preimplantation embryos using the PRINS technique.

PURPOSE: The analysis of the chromosomal constitution of human gametes and embryos is of particular importance for investigation of aneuploidy occurrence and diagnostic purposes. The PRINS method constitutes an alternative to FISH for in situ chromosomal identification. We have adapted this method to human gametes, zygotes, and preimplantation embryos. RESULTS: Chromosome-specific labeling was obtained in gametes, zygotes, and isolated blastomeres. Simultaneous detection of two or three chromosomes can be completed in less than 3 hr using fluorochrome-labeled nucleotides. CONCLUSIONS: The PRINS technique appears to be more efficient than FISH for detection and discrimination of alpha-satellite DNA sequences. The present study demonstrates the usefulness of PRINS for chromosomal screening and preimplantation diagnosis.

Aneuploidy↗

PubMed1996

Preimplantation embryo chromosome analysis by primed in situ labeling method.

OBJECTIVE: To present the use of primed in situ labeling method in preimplantation diagnosis. DESIGN: Double- and triple-primed in situ labeling were performed on 10 morphologically abnormal preimplantation embryos, using combinations of specific primers for chromosomes 9, 13, 16, 18, 21, X, and Y. SETTING: Embryos were obtained from patients at the Montpellier University Hospital. PATIENT(S): Seven women undergoing IVF at the Montpellier University Hospital. INTERVENTION(S): Isolated interphase nuclei from poor quality preimplantation embryos were prepared for primed in situ labeling technique. MAIN OUTCOME MEASURE(S): Numerical abnormalities assessed by primed in situ labeling analysis. RESULT(S): Using directly fluorescent-labeled nucleotides, the labeling reaction for three chromosomes did not exceed 2.30 hours. Only three analyzed embryos appeared to be chromosomally normal. Mosaicism, aneupoidy, and haploidy were observed in the seven other embryos. CONCLUSION(S): The primed in situ labeling method offers a simple and reliable screening tool for gender determination and aneuploidy detection. The use of this technique may contribute to significantly improve the procedure of preimplantation diagnosis.

Aneuploidy↗

PubMed1996

The PRINS technique: potential use for rapid preimplantation embryo chromosome screening.

The primed in-situ labelling (PRINS) method is an alternative to in-situ hybridization for chromosomal detection based on the use of chromosome-specific oligonucleotide primers. Using this process, we have developed a simple and semi-automatic method for rapid in-situ detection of human chromosomes. The reaction was performed on a programmable temperature cycler. Specific labelling was obtained in < 2 h reaction. Double PRINS techniques were performed on six morphologically abnormal preimplantation embryos using primers specific for chromosomes 9, 16, 18, 21, X and Y. The majority of these embryos displayed chromosomal abnormalities. The present results demonstrate that PRINS may be a simple and reliable technique applicable in human preimplantation diagnosis.

Blastocyst↗

PubMed1996

FISH and PRINS, a strategy for rapid chromosome screening: application to the assessment of aneuploidy in human sperm.

The co-utilization of FISH and PRINS techniques for in situ chromosome screening was tested on human sperm nuclei. We used a centromeric repeat probe specific for chromosome 4 for FISH. PRINS reactions were performed with alpha-satellite primers specific for either chromosomes 9 or chromosome 18. Double labeling was obtained and estimates of disomy rates were carried out for the three chromosomes.

Adult↗

PubMed1996

Double and triple in situ chromosomal labeling of human spermatozoa by PRINS.

The PRimed IN Situ (PRINS) labeling method allows rapid, specific detection of human chromosomes in situ. We have adapted the PRINS protocol to mature human sperm in combination with a 3 M NaOH protocol for simultaneous in situ decondensation and denaturation of sperm nuclei. Using fluorochrome-labeled dNTPs in a sequential PRINS reaction, the direct detection of two or three distinct chromosomes must be performed within a timespan of 3 h. The method was tested with primers specific for chromosomes 8, 9, 12, 13, 16, 18, and 21 and the X. The frequencies of disomy ranged from 0.11% to 0.34%. Chromosome-specific primers have been defined for most of the human chromosomes, including some that are indistinguishable by fluorescence in situ hybridization (FISH) with centromeric probes. Consequently, this new strategy constitutes a rapid and efficient alternative to FISH for detecting nondisjunction in human sperm.

Aneuploidy↗