Intracytoplasmic sperm injection versus conventional in-vitro fertilization: first results.
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Cytoplasm↗
Biomedical subjects
A Veiga
Publications and source records attributed to A Veiga.
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.
Animals↗
Controversies in assisted reproduction: oocyte donation. Protocols for egg donation.
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Administration, Intravaginal↗
Twin pregnancy after preimplantation diagnosis for sex selection.
A twin female pregnancy was obtained in a haemophilia carrier after two preimplantation diagnosis cycles. The embryonic sex of biopsied blastomeres was determined with the use of dual fluorescence in-situ hybridization with directly labelled DNA probes specific for the X and Y chromosome. A twin female pregnancy was confirmed by means of ultrasonography and amniocentesis at the 14th week of amenorrhoea. The patient delivered two healthy females by Caesarian section at the 37th week of pregnancy.
Adult↗
Critical evaluation of the present experience on microsurgical sperm aspiration.
Microsurgical epididymal sperm aspiration (MESA) and IVF techniques are indicated in those cases of bilateral congenital absence of the vas deferens (BCAVD) and in cases of epididymal obstruction (EO) of other aetiologies were vasoepididymostomy is not possible or has failed. Microsurgical deferential sperm aspiration (MDSA) is indicated in those cases where spermatogenesis and epididymal permeability are conserved but spermatozoa, for different causes, cannot reach the ejaculate and other therapies have failed. We have performed this procedure in 70 patients by two different human reproduction teams. Both teams achieved very similar results regarding fertilization rate: 5.5 and 7.2% in cases of BCAVD, 6.5 and 8.8% in cases of EO and 33.3 and 26.7% in cases of non-epididymal pathology (NEP). However, the fertilization rate per patient presents differences between both teams: 27 and 44.4% in BCAVD, 31 and 11% in EO and 80 and 100% in NEP. In spite of a better fertilization rate per patient in team two, it was in the other where pregnancies were achieved (7% in BCAVD, 15% in EO and 20% in NEP). One pregnancy in EO group was achieved by intracytoplasmatic sperm injection. The pregnancy rates per transfer were 25% in BCAVD, 50% in EO and 25% in NEP.
Epididymis↗
[Coronary disease and noncardiac surgery. An evaluation of the surgical risk].
Coronary artery disease is one of the leading causes of death in developed countries and one of the factors contributing to high mortality associated with noncardiac surgical procedures. This is the reason why is so important to correctly assess surgical risk in patients with ischemic heart disease. These patients can be evaluated by a simple clinic examination, electrocardiogram and chest X-ray. In asymptomatic patients or in patients with angina (Class I-II), normal electrocardiogram and chest X-ray, the operative risk is low. On the other hand, patients with severe heart failure (Class IV NYHA), unstable angina or acute myocardial infarction have a high surgical risk. The exercise stress testing must be performed in some cases in order to identify preoperative factors (electrocardiographic ischemic changes, low functional capacity) that might affect the development of cardiac events after noncardiac surgery. When not possible a thallium-dipyridamole scintigraphy should be considered. We discuss preoperative indications for coronary angiography and coronary revascularization. Coronary artery bypass surgery must be thought based on clinic severity, therapeutic results, left ventricular function and patient age, among other factors.
Coronary Disease↗
Two years of assisted fertilization by partial zona dissection in male factor infertility patients.
OBJECTIVE: To assess partial zona dissection in our routine IVF-ET program over a 2-year period. DESIGN: Partial zona dissection before insemination on the day of oocyte collection or 24 hours after unsuccessful conventional IVF. In a subgroup of patients, oocytes were randomized to either partial zona dissection before insemination or IVF. SETTING: University infertility clinic. PATIENTS: Couples who suffered principally from male factor infertility or who had failed fertilization previously. INTERVENTIONS: Micromanipulation of oocytes with partial zona dissection. MAIN OUTCOME MEASURES: Comparison of fertilization rate, embryo morphology, and implantation rate between partial zona dissection inseminated oocytes and conventional IVF inseminated oocytes (controls). RESULTS: Five pregnancies were established in 199 patients. The incidence of polyspermy was significantly higher in the partial zona dissection group than in conventional IVF (4.8% versus 1.3%). There were no significant differences in the remaining parameters. The fertilization rate of partial zona dissection and reinsemination was significantly higher than conventional IVF insemination (13.6% versus 4.5%) but similar to the rate obtained when partial zona dissection was applied before insemination (13.6% versus 15.7%). CONCLUSIONS: Oocytes treated by partial zona dissection did not exhibit a greater fertilization rate than conventional IVF inseminated oocytes. Partial zona dissection may not be a useful technique for treating severe male factor infertility.
Adult↗
Sephadex filtration and human serum albumin gradients do not select spermatozoa by sex chromosome: a fluorescent in-situ hybridization study.
Fluorescent in-situ hybridization (FISH) of decondensed sperm nuclei has been used directly to evaluate the enrichment efficiency of human sperm separation using Sephadex gel filtration and human serum albumin (HSA) gradients. Control and processed spermatozoa were fixed and their nuclei decondensed. In-situ hybridization was carried out with a Y-specific DNA probe (DYZ1). Sephadex filtration yielded 52.5% Y-chromosome-bearing spermatozoa, HSA separation resulted in 49.4% Y-chromosome-bearing spermatozoa and in the untreated control sample the percentage of Y spermatozoa was 49.3%. Statistical analysis revealed no significant differences between the selection methods employed and the controls, and no real enrichment for X- or Y-bearing spermatozoa was detected for any of the selection methods assayed. The usefulness of the protocols reported for selection of spermatozoa by sex chromosome in couples at risk for X-linked diseases is discussed.
Cell Separation↗
Establishing a program of oocyte donation in Brazil.
Oocyte donation is a novel alternative for the treatment of patients who have infertility associated with ovarian failure. Both IVF-ET and GIFT represent new techniques of treatment for this group of patients. Synchronization between donor and recipient is very simple and also flexible. In our study population, four patients received oocyte or embryo donation after at least 20 days of E replacement, and two of them conceived a clinical pregnancy. Apparently, the flexibility of our protocol of E replacement allows an extension of the proliferative phase in cases that need to have additional time to synchronize the recipient's cycle to that of the donors.
Adult↗
Indications for oocyte donation.
Donated oocytes were transferred on 92 occasions to 87 women without gonadal function and 5 with functional ovaries. Twenty-three pregnancies were established (25% pregnancy rate), 9 after transfer of fresh embryos in 30 synchronous donor and recipient cycles and 14 after transfers of frozen-thawed embryos in 62 asynchronous donor and recipient cycles. Twenty-two pregnancies were obtained in agonadal patients (25.3% pregnancy rate) and 1 in a gonadal woman (20% pregnancy rate). Pregnant women were younger than those who did not become pregnant, but the difference was not significant. The pregnancy rate was higher when intra-Fallopian transfer was performed (46%) as compared with intrauterine transfer (21.5%) and when micronized progesterone was given intravaginally (pregnancy rate 30.3%) as compared to intramuscularly injected natural progesterone in oil (pregnancy rate 22%). Twenty healthy infants have been born including one set of twins; four pregnancies miscarried.
Adult↗
Chromosome anomalies in mouse zygotes treated by growth hormone-releasing factor.
The incidence of chromosome anomalies was studied in fertilized oocytes in two groups of hybrid mice in which superovulation was induced by gonadotrophins and growth hormone-releasing factor (GRF) supplementation or gonadotrophins alone (controls). The rate of fertilization was significantly higher among GRF-treated females than among controls (74.1 versus 84.7%; P < 0.013). Cytogenetic data were obtained in 262 fertilized oocytes (89 from control females and 173 from GRF-treated females). The frequency of aneuploidy, calculated as twice the frequency of hyperhaploidy was 2.31% in GRF-treated females and 2.24% in controls (NS). The use of GRF to treat female mice did not adversely affect the maturation process of oocytes nor did it induce an increased frequency of aneuploidy.
Animals↗
Are clinical and biological IVF parameters correlated with chromosomal disorders in early life: a multicentric study.
A multicentric study was carried out to analyse in a large series: (i) the chromosomal status of unfertilized oocytes, (ii) errors at fertilization and (iii) the chromosomal complement of cleaved embryos. Parameters such as type of sterility, maternal age, stimulation treatment, doses of gonadotrophins administered and oocyte preincubation time before insemination were studied in relation to the incidence of chromosome abnormalities. Twenty-six per cent of the unfertilized oocytes and 29.2% of the embryos had chromosome anomalies. Maternal age significantly increased the rate of aneuploidy in oocytes: 38% in patients over 35 years (versus 24% in younger patients). Fertilization-related abnormalities were significant, i.e. 1.6% parthenogenesis and 6.4% polyploidy. Unexplained infertility was correlated with an increase in the rate of parthenogenesis (4.2%) when compared with tubal infertility (1.2%). Triploidy was found to be correlated with three parameters. A lower rate of triploidy was observed in the group of couples referred because of male sterility (1.9% versus 6.3% for tubal sterility), in HMG-treated patients (2.4% versus 7% with analogues of LHRH/HMG) and with a short 2-h preincubation time before insemination (3% versus 7.2% for greater than 2 h). A general model for natural selection against embryos carrying a chromosome imbalance was proposed.
Chromosome Aberrations↗
Retained T-tube fragment: removal using ERCP with papillotomy.
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Adult↗
Pregnancy after the replacement of a frozen-thawed embryo with less than 50% intact blastomeres.
Early embryo freezing with saccharose and propanediol gives a survival rate of 62% of the embryos if 4 cell embryos with only one intact blastomere after thawing are included. The first pregnancy achieved with such an embryo is reported as well as preliminary results obtained in our IVF programme using the French method.
Blastomeres↗
Chromosome studies in oocytes and zygotes from an IVF programme.
Chromosome studies have been carried out in 117 oocytes, 17 one-cell zygotes and four, two- to four-cell zygotes in our IVF programme. Three apparently unfertilized oocytes were, in fact, diploid zygotes. Two of 14 apparently polyspermic zygotes were also diploid. One zygote with four pronuclei was pentaploid. This indicates that pronuclei can either be confused with other cytoplasmic structures, like vacuoles, or be eliminated. Endoreduplication was observed in one tetraploid, apparently polyspermic zygote, and in one two-cell degenerated zygote. The incidence of aneuploidy in unfertilized oocytes, taken as twice the level of hyperhaploidy, was 15.4%. Five oocytes showed fragmented metaphase II chromosomes (4.3%). The incidence of unreduced oocytes, due to a lack of extrusion of the first polar body, was 6.8%. Thus the total number of potentially aneuploid, polyploid or non-viable zygotes due to chromosome aberrations in the oocyte was 26.5%.
Aneuploidy↗
Pre- and postsynaptic localization of 3H-imipramine binding sites in rat cerebral cortex.
The subcellular localization of 3H-imipramine binding sites in brain was investigated with the aim of learning about the possible mechanism of action of this antidepressant. The rat cerebral cortex was submitted to a systematic fractionation and both the nuclear and the synaptosomal fractions were purified by gradient centrifugation. Using a centrifugation assay for the binding, we found that the synaptosomal membranes had the highest specific activity and showed two binding sites, one of high affinity with a KD of 14 nM and a Bmax of 3.1 pmol per mg protein, and another of lower affinity with a KD of 99 nM and a Bmax of 14.2 pmol per mg protein. Purified nuclei have a lower specific activity than the synaptosomal membrane, specially when expressed per g tissue. On the other hand, myelin and capillaries have few binding sites. Synaptosomal membranes were treated with 0.1, 0.2 and 0.5% Triton X-100 to dissolve the pre- and post-synaptic membrane and submitted to 3H-imipramine binding in the presence of the detergent or after washing of the residue. The results obtained suggest that although most 3H-imipramine binding sites are localized pre-synaptically, a certain proportion are post-synaptic. These findings are discussed in relation to previous studies from this laboratory on the localization of central receptors with reference to the synaptic region and to the antidepressant action of imipramine.
Animals↗
Human male infertility: chromosome anomalies, meiotic disorders, abnormal spermatozoa and recurrent abortion.
Human male infertility is often related to chromosome abnormalities. In chromosomally normal infertile males, the rates of chromosome 21 and sex chromosome disomy in spermatozoa are increased. Higher incidences of trisomy 21 (seldom of paternal origin) and sex chromosome aneuploidy are also found. XXY and XYY patients produce increased numbers of XY, XX and YY spermatozoa, indicating an increased risk of production of XXY, XYY and XXX individuals. Since XXYs can reproduce using intracytoplasmic sperm injection (ICSI), this could explain the slight increase of sex chromosome anomalies in ICSI series. Carriers of structural reorganizations produce unbalanced spermatozoa, and risk having children with duplications and/or deficiencies. In some cases, this risk is considerably lower or higher than average. These patients also show increased diploidy, and a higher risk of producing diandric triploids. Meiotic disorders are frequent in infertile males, and increase with severe oligoasthenozoospemia (OA) and/or high follicle stimulating hormone (FSH) concentrations. These patients produce spermatozoa with autosomal and sex chromosome disomies, and diploid spermatozoa. Their contribution to recurrent abortion depends on the production of trisomies, monosomies and of triploids. The most frequent sperm chromosome anomaly in infertile males is diploidy, originated by either meiotic mutations or by a compromised testicular environment.
Abortion, Habitual↗
Applications of ovarian tissue transplantation in experimental biology and medicine.
Nowadays, high-dose chemotherapy and radiotherapy treatments for cancer are more effective but can severely affect the ovarian follicular store, compromising the fertility of surviving young patients. A promising alternative to prevent fertility loss in these patients is the cryopreservation and transplantation of ovarian tissue. Slices of animal and human ovarian tissue have been shown to survive the cryopreservation process. After transplantation, follicular development and restoration of hormone secretion have been observed in animal and human studies. This review addresses recent developments on ovarian tissue transplantation in animals and humans. We also illustrate the indications and technical difficulties of the procedure and the ethical issues that should be considered.
Animals↗