José Egozcue

In vitro fertilization plus preimplantation genetic diagnosis in patients with recurrent miscarriage: an analysis of chromosome abnormalities in human preimplantation embryos

OBJECTIVE To analyze the incidence of numeric chromosomal abnormalities in preimplantation embryos from women with unexplained recurrent miscarriage (RM) so as to seek an etiology and to determine whether the use of IVF may be indicated to treat these cases. DESIGN Prospective controlled study. SETTING University laboratory of reproductive genetics and a tertiary referral center for infertility. PATIENT(S) Nine women with a mean (+/-SD) of 3.9 +/- 0.6 RMs who were undergoing IVF and preimplantation genetic diagnosis, and a control group of young (n = 10) and older (n = 6) patients who were undergoing preimplantation genetic diagnosis because of sex-linked diseases. INTERVENTION(S) In vitro fertilization, embryo culture for 72 hours, blastomere biopsy, and analysis of chromosomes 13, 16, 18, 21, 22, X, and Y with the use of fluorescent in situ hybridization. Transfer of chromosomally normal embryos into the uterus. MAIN OUTCOME MEASURE(S) Numeric chromosomal abnormalities in human embryos. RESULT(S) Sixty-six embryos from patients with RM were compared with 62 embryos from young patients and 41 embryos from older patients. There was a significant increase in the rate of abnormal embryos in the patients with RM and the older patients compared with the controls. Abnormalities in most of the chromosomes studied were higher in the RM group than in the control group, especially those affecting chromosome 13. CONCLUSION(S) There was an increase in numeric chromosomal abnormalities in preimplantation embryos from women with RM that could be the cause of infertility in many couples with unexplained RM. The use of IVF in such circumstances may be indicated if successful preimplantation genetic diagnosis is added to the procedure.

Implications of sperm chromosome abnormalities in recurrent miscarriage

Purpose:Our purpose was to assess the existence of sperm chromosome abnormalities in recurrent pregnancy loss in an assisted reproduction program.Methods:In this prospective study, 12 sperm samples from couples undergoing in vitro fertilization with two or more first-trimester spontaneous abortions were analyzed. Diploidy and disomy in decondensed sperm nuclei were assessed for chromosomes 13, 18, 21, X, and Y using two- and three-color fluorescence in situ hybridization.Results:Sex chromosome disomy in sperm samples from recurrent abortion couples was significantly increased compared to that from internal controls (0.84% vs 0.37%). In a subpopulation of seven couples who underwent oocyte donation, mean frequencies for sex chromosome disomy (1%) were even higher and diploidy (0.43%) was also significantly increased.Conclusions:These results suggest an implication of sperm chromosome abnormalities in some cases of recurrent pregnancy loss.

Evaluation of cytogenetic analysis for clinical preimplantation diagnosis

OBJECTIVE To evaluate the feasibility of using cytogenetic analysis in preimplantation diagnosis. DESIGN Two different biopsy protocols (chemical drilling and zona cutting) and two fixation methods were tested in a mouse model. Afterwards, the efficiency of obtaining chromosome preparations from untransferable human embryos depending on the method used to obtain the blastomeres (embryos biopsy or removal of the zona pellucida and blastomere disaggregation) was determined. The chances of obtaining chromosome preparations depending on the type of embryo (haploid, diploid, triploid, and apparently unfertilized) were also evaluated. RESULTS Results from the mouse model showed that chemical drilling yields better results than cutting in terms of metaphases per biopsied embryo and surviving rate after biopsy. In human embryos, biopsy of diploid embryos produced 46.6% chromosome preparations, while 29% were obtained after blastomere disaggregation and 20.4% when biopsying triploid embryos. CONCLUSIONS These results suggest that the disaggregating procedure and triploid embryos cannot be considered as good models to assess the feasibility of cytogenetic analysis in preimplantation diagnosis. Poor chromosome quality and loss during fixation are the main problems to use cytogenetics in preimplantation diagnosis; a combination of cytogenetics and other techniques is suggested in cases of balanced translocations.

Banding patterns of the chromosomes of man and the chimpanzee

SummaryA comparison of the banding patterns of the chromosomes of man (Homo sapiens) and the chimpanzee (Pan troglodytes) using G (Giemsa) and Q (quinacrine) banding techniques shows that the differences between the karyotypes of the two species are the result of a few simple structural rearrangements, which include one centric fusion, five pericentric inversions, one paracentric inversion and the absence of one secondary constriction.ZusammenfassungEin Vergleich der Bandenmuster der Chromosomen des Menschen (Homo sapiens) und des Schimpansen (Pan troglodytes) bei Anwendung der G(Giemsa)- und Q(Quinacrin)-Bandentechnik zeigt, daß die Unterschiede zwischen den Karyotypen beider Species das Ergebnis einiger weniger einfacher Umstrukturierungen sind, nämlich einer zentrischen Fusion, 5 perizentrischen Inversionen, einer parazentrischen Inversion und des Fehlens einer sekundären Konstriktion.

Decreased sensitivity to the cytogenetic effects of bleomycin in individuals occupationally exposed to ionizing radiation

In the present work, 12 individuals occupationally exposed to ionizing radiation and 11 unexposed ones were studied to determine the cytogenetic effect of a challenge dose of bleomycin on their phytohemagglutinin stimulated lymphocytes. After bleomycin treatment, the frequencies of chromatid breaks and gaps were significantly lower in the exposed population (p < 0.025 for both types of chromatid alterations). These results could indicate that occupational exposure to ionizing radiation can induce an adaptive response that can be detected by a subsequent treatment with bleomycin.

Human sperm chromosome studies in a reciprocal translocation t(2;5)

SummarySperm chromosome complements have been studied in a man heterozygous for a reciprocal translocation t(2;5)(p11;q15). Human sperm chromosomes were obtained after fertilization of zona-free hamster eggs. A total of 75 human sperm metaphases were analysed. Of the complements studied, 59 (78.6%) resulted from a 2:2 segregation and 16 (21.3%) from a 3:1 segregation, 4:0 segregation was not observed. Our results indicate that at least 36% of sperm complements were unbalanced with respect to the translocation. The frequency of other chromosome anomalies unrelated to the translocation was 16%.

Comparative genomic hybridization analysis of transitional cell carcinomas of the renal pelvis.

We used comparative genomic hybridization to analyze 10 primary tumor samples from patients with transitional cell carcinoma of the renal pelvis. The most frequent loss was located at 9q, that is, in 50% of the tumors. Gains of DNA sequences were most frequently observed in chromosome regions 1q21 approximately q23, 2p23 approximately p25, 8q21.1 approximately q22 and in the whole chromosome 20. High level amplifications at 1q21 approximately q25, 6p22 approximately p23, 8q21 approximately q22, 8q22 approximately q24.1, 11q13, and 12q14 approximately q21 were detected. Most of these regions have previously been reported to be involved in transitional cell carcinoma of the bladder, thus confirming the importance of an increasing number of chromosome imbalances in the development and progression of this type of tumors.

Trisomy 7 may be a primary change in non-invasive transitional cell carcinoma of the bladder

We describe two cases of transitional cell carcinoma of the bladder associated with trisomy 7. In one of them, trisomy 7 was the only chromosome abnormality observed. In the second case, trisomy 7 was found in 25 (80.6%) of the metaphases; in two of them this was the only anomaly, while in three metaphases trisomy 8 was also present, and in other two trisomy 10 was also observed. Our results suggest that trisomy 7 could be a primary change in TCC, and a review of the literature indicates that when it is present as the sole karyotypic abnormality is may be associated with a non-invasive behavior of the tumor.

Cytogenetic characterization of a familial papillary renal cell carcinoma

We describe the first case of a familial renal cell carcinoma cytogenetically characterized as a papillary renal cell carcinoma. Cytogenetic and molecular studies were performed on primary renal cell carcinomas and normal kidney tissue from two members of the same family. Both patients showed a normal constitutional karyotype. The two tumors analyzed from the first patient showed the numerical chromosome alterations characteristic of papillary renal cell carcinomas. From the four tumors analyzed in the second patient, three of them presented the cytogenetic pattern of papillary renal cell tumors, and the fourth showed only structural chromosome abnormalities with the presence of a del(7)t(7;7) or dup(7) in all metaphases analyzed. Chromosome 3 was cytogenetically unaffected in all tumors from both patients, and restriction fragment length polymorphism analysis performed with probe pEFD145 (3p21.1-p23) did not detect any loss of heterozygosity.

Effect of LSD-25 on mitotic and meiotic chromosomes of mice and monkeys.

SummaryChromosomal studies were carried out in bone marrow and testes of mice treated with lysergic acid diethylamide (LSD-25) in acute and chronic experiments, in blood cultures of rhesus monkeys (Macaca mulatta) treated with LSD-25 in vitro, and in blood cultures and testicular preparations of rhesus macaques treated with LSD. No increase in chromosomal damage was observed in bone marrow or testes, but all blood cultures treated with LSD in vitro and some of the blood cultures from rhesus macaques treated in vitro showed a significant increase in chromosomal breaks and rearrangements.