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Biomedical subjects

J M Luciani

Publications and source records attributed to J M Luciani.

At least 19 recordsLinked to original sources
PubMed1992

Infertility in human males with autosomal translocations. II. Meiotic studies in three reciprocal rearrangements, one showing tertiary monosomy in a 45-chromosome individual and his father.

The meiotic prophase behavior of three human reciprocal autosomal translocations is presented. Each translocation was ascertained among men attending an infertility clinic. Two involved chromosomes 3 and 5, with breakpoints in different places. Quadrivalents were seen in every cell. The third translocation was a rare t(11q;15q) rearrangement in a 45-chromosome individual with tertiary monosomy. The long product of the translocation was retained in the karyotype over two generations of the family, the short product having been lost. At meiotic prophase, a trivalent was seen in every cell; in 60% of the nuclei, the short arm of the trivalent was closely associated with the XY bivalent. The transmission and phenotypic effects of tertiary monosomy in man and the mouse are discussed.

Chromosome Deletion↗
PubMed1991

Three dimensional reconstruction of human pachytene spermatocyte nuclei of a 17;21 reciprocal translocation carrier: study of XY-autosome relationships.

A study of XY-autosome relationships at the pachytene stage in an infertile 17-21 reciprocal translocation carrier was undertaken by means of three dimensional reconstruction. Synaptonemal complexes and the sex vesicle were analysed on electron microscopic serial sections and the reconstruction was performed on transparent sheets and on a Samba 2000 (Alcatel TITN) image analysis system. All asynapsed segments were entirely included in the sex vesicle, the chromatin fibre of the autosomes and sex chromosomes being tightly intermingled. In one nucleus, the four arms of the quadrivalent were paired, except around the breakpoints where an interstitial asynapsis was observed. In the other nuclei, a terminal asynapsis involving one or two arms of the quadrivalent was found. In the sex vesicle, autosomal asynapsed segments showed the same morphological characteristics as those of X and Y chromosomes. This observation agrees with the hypothesis of the extension of gene inactivation from sex chromosomes to autosomes.

Cell Nucleus↗
PubMed1991

Epididymal sperm aspiration in conjunction with in-vitro fertilization and embryo transfer in cases of obstructive azoospermia.

Epididymal sperm aspiration is a new treatment for vasal agenesis. In previous reports, epididymal spermatozoa resulted in pregnancy by utilizing in-vitro fertilization (IVF) or gamete intra-Fallopian transfer (GIFT). We sought to investigate the efficacy of epididymal sperm aspiration in conjunction with IVF in patients with congenital absence of the vas deferens or with secondary extended obstruction of spermatic ducts. Fifty-eight attempts were performed in 23 patients (25-50 years). Eight patients (34.7%) had vasal agenesis and 14 (60.8%) presented with vasal secondary extended obstruction. The sperm count was adequate (greater than or equal 20 x 10(6)/ml) in 13.8% of sperm retrievals and sperm motility of 20% was obtained in 15.5% of sperm retrievals. Fourteen attempts at IVF were performed with epididymal sperm counts of 2-44 x 10(6)/ml and motilities of 0-45%. A mean of six mature oocytes (0-13) were inseminated in each case. Five embryo transfers were performed in five patients' wives (35.7%) and two couples had an early pregnancy loss (14.2%). Epididymal sperm aspiration is an advance in treating such patients, as an adequate number of mature spermatozoa can be obtained and used for IVF. However, spermatozoa directly aspirated from the proximal epididymis and with fertilizing capacity in vitro, gave a high rate of embryo degeneration (greater than 50%) after embryo transfer.

Adult↗
PubMed1990

Infertility in human males with autosomal translocations: meiotic study of a 14;22 Robertsonian translocation.

Pachytene analysis was undertaken in a male patient heterozygous for a 14q22q Robertsonian translocation. The relatively low rate of XY autosome association led us to examine the relationships existing between the chromosomes involved in the translocation, the rate of XY-autosome association and the degree of spermatogenic failure. Cytogenetic investigations in infertile men and the results of the meiotic studies suggest a direct correlation between the frequency of XY-autosome association at pachytene and the degree of spermatogenic failure. Whether associations arise as a consequence or cause of germ cell failure is still not certain.

Adult↗
PubMed1990

[Incidence of structural chromosomal abnormalities in spermatogenesis in man].

Infertility due to gametogenic failure is frequently associated with structural autosomal abnormalities. Recent meiotic studies at the pachytene stage undertaken in human infertile heterozygous carriers for such rearrangements have regularly shown a synaptic failure around the breakpoints, an association of the translocation figure with the sex chromosomes and the frequent involvement of the acrocentric chromosomes. Two main models were proposed to explain the male sterilizing effect of autosomal rearrangements: the impairment of spermatogenesis could be the result of: 1) the XY-autosome interaction; 2) the pairing disruption around the breakpoints at the pachytene stage. They could contribute significantly to germ-cell atresia.

Chromosome Aberrations↗
PubMed1989

Differential associative behaviour of mitotic and meiotic acrocentric chromosomes.

A comparative study of the association of mitotic acrocentric chromosomes and acrocentric bivalents at the pachytene stage shows that at least two factors can act in the associative behaviour of these chromosomes: (1) Nor activity and (2) the presence of satellite DNA in the short arms of these chromosomes. These factors do not act with the same intensity in the two cell lines studied. In lymphocytes, Nor activity prevails, whereas satellite DNA plays the main role in the association of acrocentric chromosomes in germ cells at the pachytene stage.

Chromosomes↗
PubMed1989

Precise in situ localization of NCAM, ETS1, and D11S29 on human meiotic chromosomes.

In order to sublocalize NCAM, ETS1, and the anonymous DNA fragment D11S29 within 11q23, in situ hybridization was performed on pachytene bivalents. Analysis of the grain distribution within the band 11q23 indicated that the chromosomal sublocalization of both NCAM and D11S29 was in 11q23.1, whereas ETS1 was found to be localized in 11q23.3. These results clearly demonstrate the usefulness of in situ hybridization applied to pachytene bivalents to obtain accurate gene sublocalization.

Chromosome Mapping↗
PubMed1989

[Intraperitoneal insemination].

Intra-perineal insemination is a technique used in assisted reproduction. The principle is to stimulate the ovaries, to obtain the partner's sperm and to prepare it by similar techniques to those used in in-vitro fertilization so that the sperm can be placed near the ovaries in the Pouch of Douglas by a direct puncture of the posterior vaginal fornix without using anaesthesia. The woman's pelvis has to be absolutely normal. This technique is useful in cases of unexplained sterility, cervical sterility and inadequate sperm function.

Adult↗
PubMed1988

Differential elongation of autosomal pachytene bivalents related to their DNA content in human spermatocytes.

The establishment of the complete karyotype of human pachytene spermatocytes reveals differences in stretching of chromosomes between meiosis and mitosis. Bivalents or specific regions of bivalents which exhibit many R-bands are particularly elongated. In mitotic chromosomes, the DNA contained in such bands is known to be early replicating. The study of variations in the total length and the centromeric index of bivalent 1 suggests that differential elongation of pachytene bivalents is a premeiotic event, taking place during the last DNA replication.

Chromosome Banding↗
PubMed1988

The microtubular cytoskeleton and chromosomes of unfertilized human oocytes aged in vitro.

To detect structural alterations in human oocytes that may give rise to predisposition to aneuploidy, unfertilized human oocytes from an IVF programme were processed for indirect anti-tubulin immunofluorescence. The spindle of oocytes aged for 2 days is rather small, and bi- or multipolar. Chromosomes are no longer aligned at the spindle equator but are scattered all over the degenerating spindle. This implies that human oocytes aged for 2 days may no longer be able to develop into a chromosomally balanced, normal embryo. In oocytes aged for 3-4 days the chromosomes become more decondensed and form a restitution nucleus. Microtubules radiate out from the latter towards the cell periphery and form a network of fibres in the cytoplasm. A similar alignment of tubules is found in unfertilized, activated oocytes. Oocytes with an aberrant cytoskeleton and chromosomal array were predominantly obtained from aged females. They include two binucleated oocytes with two sets of chromosomes and two oocytes with displaced chromosomes one of which had a tripolar spindle.

Adult↗
PubMed1988

Meiotic analysis of two human reciprocal X-autosome translocations.

Two cases of human reciprocal X-autosome translocation, t(X;12) and t(X;2), are described in sterile males, along with meiotic findings. Each carrier had inherited the translocation from his mother. Both showed azoospermia and germ-cell maturation arrest at the primary spermatocyte level, with most cells being arrested at the pachytene stage. A few metaphase I (MI) divisions were found, with occasional metaphase II cells being seen in the t(X;2) carrier. MI air-dried preparations gave clear evidence of chain quadrivalent formation. In the t(X;2) heterozygote, the pairing characteristics of the quadrivalent at pachytene were also analyzed in electron microscopic spreads. Disturbance of pairing around the breakpoints characterized most quadrivalents, and there was evidence in about 20% of the cells that nonhomologous pairing had taken place between the translocated chromosomes and the normal chromosome 2. Comparisons are made with similar nonhomologous pairing configurations seen at pachytene in quadrivalents of male reciprocal X-autosome translocations of the mouse.

Adult↗
PubMed1987

Pachytene analysis in a 17;21 reciprocal translocation carrier: role of the acrocentric chromosomes in male sterility.

Pachytene analysis was undertaken in an infertile male, heterozygous for a 17;21 reciprocal translocation. The quadrivalent was identified by its configuration and chromomere pattern. A non-random association was found between the quadrivalent and the sex vesicle in 77% of the pachytene nuclei analysed. In 13.1% of the cells the contact with the sex vesicle was established by the terminal chromomere of the two chromosomes 21; in 63.9% of the cells, the entire region of the breakpoints was completely hidden by the sex vesicle. In some nuclei asynapsis was found in the region of the breakpoints. The nature of the contact between the quadrivalent and the sex vesicle is discussed in this paper. It is proposed that the acrocentric chromosome favours the contact between the quadrivalent and the sex vesicle, and increases the risk of sterility in male carriers of Robertsonian translocations and of reciprocal translocations involving one acrocentric chromosome.

Adult↗
PubMed1987

[Estimation of the quality of embryos obtained during fertilization in vitro as a function of their morphology].

Embryo quality after IVF should allow provisions for their pregnancy potential. We have classified all the transferred embryos into 4 types according to morphological criteria and we have studied the implantation rate of the different types. The results show: That pregnancies have been obtained with the 4 types of embryos. That it has been impossible to demonstrate statistically significant differences between the different types of transferred embryos even if embryos morphologically normal seem to be more favourable than others to induce a pregnancy. That the average implantation rate for each transferred embryo is of 14.4%.

Embryo Implantation↗
PubMed1986

Direct estimation of the non-disjunction rate at first meiotic division in the human male. Preliminary results.

Chromosomal analysis of 100 second metaphases from 19 men attending an infertility clinic for various reasons was carried out to estimate the rate of non-disjunction occurring at first meiotic division. Second metaphases were selected on the basis of the good spread of their chromosomes. Karyotypes were performed using the relative length of the chromosomes and the centromeric index. Among aneuploid cells, only those containing a hyperhaploid complement (24) were regarded as informative. Of the 100 MII cells, two were hyperhaploid. The frequency of aneuploid MII cells following non-disjunction at first meiotic division is compared to the rate of aneuploid spermatozoa observed after using fertilization of zona-free golden hamster eggs.

Adult↗
PubMed1986

Loop formation and synaptic adjustment in a human male heterozygous for two pericentric inversions.

Pachytene analysis was undertaken in an infertile male heterozygous for two pericentric inversions of chromosomes 1 and 9. The synaptic behaviour of the bivalent 1 inversion was the most informative. Analysis of the chromomere pattern combined with centromeric heterochromatin staining allowed precise description of synaptic initiation and extension leading to the homosynapsed loop. These techniques also allowed demonstration of the existence of heterosynapsis following alignment of the inverted segments. Non-homologous synapsed bivalents had the morphological aspects of straight bivalents with two distant blocks of centromeric heterochromatin. The numbering of the autosomal bivalent chromomeres at various successive phases of the inversion loop behaviour of bivalent 1 permitted us an alternative approach to the timing of pachytene.

Adult↗
PubMed1986

Random acrocentric bivalent associations in human pachytene spermatocytes. Molecular implications in the occurrence of Robertsonian translocations.

Acrocentric bivalent associations were studied in 232 human male germ cells at pachytene in order to understand better the preferential involvement of chromosomes 13, 14, and 21 in Robertsonian translocations. The tendency of each acrocentric bivalent to associate with another was not correlated with NOR activity, as measured by silver staining. Good agreement was noticed between their ability to associate and the amount of satellite DNA in human acrocentric chromosomes. The distribution of two-by-two acrocentric bivalent associations was random. In order to reconcile this result with the nonrandom distribution of Robertsonian translocations, a molecular hypothesis is proposed. The model is based on homology of recombinational sites, interspersed at regular interval in satellite DNA, which could increase the probability of accidental unequal crossing-over between two specific acrocentric chromosomes.

Aged↗
PubMed1986

Meiotic behaviour of familial pericentric inversions of chromosomes 1 and 9.

Pachytene analysis was carried out in two infertile brothers, one heterozygous for two pericentric inversions of chromosomes 1 and 9, the second heterozygous for the pericentric inversion of chromosome 1. The synaptic behaviour of the bivalent 1 inversion was the most informative. Analysis of the chromomere pattern combined with centromeric heterochromatin staining and synaptonemal complexes visualization allowed precise description of synaptic initiation and extension leading to the homosynapsed loop. Heterosynapsis following alignment of the inverted segments was demonstrated. Non-homologous synapsed bivalents had the morphological aspects of straight bivalents with two distant blocks of centromeric heterochromatin. The possible sterilizing effect caused by the autosomal inversion is discussed.

Adult↗