Biomedical subjects
Publications and source records attributed to A Pellicer.
We present two cases in which an anatomical structure, the calcar avis, and a normal variant, a bifid choroid plexus, mimicked abnormalities on routine prenatal ultrasound examination. To the best of our knowledge these pitfalls have only been described in neonates. A familiarity with these false images is important to avoid erroneous diagnoses.
BACKGROUND: Primary non-Hodgkin lymphoma (NHL) of the vagina is a rare location. Its association with the Epstein-Barr virus (EBV) has been only reported in another case. We present a new case, emphasizing the oncogenetic relevance of EBV. CASE REPORT: A 45-year-old woman with a pelvic pain revealed in her vaginal inspection a thick and hard vaginal plug with a "paving stone" appearance. The biopsy reported a vaginal non-Hodgkin lymphoma type B of intermediate cell, with positive result for EBV. After treatment, a complete remission was obtained. CONCLUSION: The EBV is the main responsible for the non-Hodgkin lymphoma; classified as a group I carcinogen, it has been associated with a variety of neoplastic tumors, although it is unusual with extranodal type B diffuse lymphoma.
PURPOSE: We aimed to establish the influence of the parameters affecting artificial insemination (AI) results in order to describe the ideal situations to achieve the best results as well as to adequately counsel the patients undergoing these treatments about their pregnancy chances. METHODS: We performed a controlled retrospective clinical study over more than one decade in a total of 1858 cycles in 710 patients. Clinical histories and computer registers were systematically reviewed between January 1990 and June 2002. We analyzed the influence of diverse factors affecting AI results such as patient's age, ovarian stimulation, and seminal characteristics to offer a detailed description of the technique. RESULTS: Less than 35-years-old, smooth ovarian stimulation and 5 million of progressive motile sperm inseminated two consecutive days are the optimum conditions for achieving good results. Also, period of time that sperm remained frozen do not affect the result. Furthermore, we present the likely or expected outcomes of these treatments depending on the male and female etiologies. CONCLUSIONS: We discourage AI in aged patients, and strongly recommend undergoing ovarian stimulation. Nonetheless, we must reach an adequate amount of sperm with good motility in order to inseminate with maximum guaranties of success.
BACKGROUND: An increased incidence of numerical chromosomal abnormalities has been reported in the ejaculated spermatozoa of infertile patients. However, there are few cytogenetic studies of testicular and epididymal spermatozoa, and their results are still controversial. METHODS: Fluorescence in-situ hybridization (FISH) analysis of chromosomes 13, 18, 21, X and Y was performed on seven testicular samples and two epididymal samples from patients with obstructive azoospermia (OA), and on 13 testicular samples from patients with non-obstructive azoospermia (NOA). Five ejaculated sperm samples from normozoospermic fertile donors were evaluated as a control group. RESULTS: Both epididymal sperm samples showed normal FISH results for the parameters analysed when compared with those of the control group. FISH results were abnormal in 29% (two of seven) of testicular samples from OA patients and in 54% (seven of 13) of those from NOA patients, although this difference was not statistically significant. Testicular samples from OA patients showed a significant increase of disomy for sex chromosomes (P<0.01), whereas NOA patients displayed significantly higher rates of diploidy (P<0.0001) and disomy for chromosomes 13 (P<0.0001), 21 (P<0.001) and sex chromosomes (P<0.0001) than the control group. CONCLUSIONS: Testicular spermatozoa from azoospermic patients present increased rates of chromosomal abnormalities, mainly of the sex chromosomes, which are particularly high in NOA patients.
The administration, to rats, of a combination of pregnant mares serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) in high doses induces the ovarian hyperstimulation syndrome (OHSS) which is characterized by increased vascular permeability (VP) and simultaneous overexpression of vascular endothelial growth factor (VEGF) in ovarian cells. hCG has a longer half-life than LH and a greater biological activity, expressed in a higher incidence of complications such as OHSS. Similarly, FSH may also be related to the ovulatory changes within the follicle as there is a simultaneous surge in spontaneous cycles. The aim of this study was to compare the capacity of hCG, FSH and LH to induce ovulation and simultaneously prevent OHSS in the animal model. Immature female rats were treated with 10 IU PMSG for 4 days, and ovulation was triggered with saline, 10 IU hCG, 10 IU FSH, 10 IU LH or 60 IU LH. The number of oocytes ovulated into the tubes, VP and mRNA VEGF expression were evaluated and compared. All the hormones employed were as effective at triggering ovulation, with similar significant P values when compared with the control for which saline was used. The use of 10 IU LH resulted in significantly lower VP and VEGF expression than that seen in the groups treated with 10 IU hCG, 10 IU FSH or 60 IU LH. In conclusion, FSH and hCG, as well as a sixfold increase in LH, displayed similar biological activities, including increased VP due to excessive VEGF expression. The use of lower doses of LH produced similar rates of ovulation, while preventing the undesired changes in permeability. These experiments should therefore encourage clinicians to determine the optimal dose of LH to be employed in women in order to trigger ovulation and, at the same time, avoid the risk of OHSS.
Convincing evidence supports the role of ovarian-origin vascular endothelial growth factor (VEGF) in inducing vascular permeability (VP) and ascites associated with ovarian hyperstimulation syndrome (OHSS) in mammals, including humans. A circulatory dysfunction has been described in every woman treated with gonadotropins for in vitro fertilization. It is not known, however, whether the action of gonadotropins also includes up-regulation of the VEGF receptor-2 (VEGFR-2) and whether increased VP is also found when milder stimulation is used. Thus, we applied an OHSS animal model to answer these questions. Immature female rats were stimulated with saline (control group) or with high (10 IU of eCG x 4 days + 30 IU hCG, OHSS group) or mild (10 IU of eCG + 10 IU of hCG, mild-stimulation group) doses of gonadotropins. The VP and the expression of whole-VEGF and VEGFR-2 mRNAs were analyzed through time-course experiments (0, 24, 48, and 96 h after hCG). Although eCG increased VP and the expression of VEGF and VEGFR-2 mRNAs in the ovaries of both mild- and OHSS-stimulated animals, hCG further augmented these parameters and produced the highest values after 48 h. A linear correlation was found between increased expression of VEGF and VEGFR-2 mRNAs and enhanced VP in both mild and OHSS groups. Immunohistochemistry showed the presence of VEGF and VEGFR-2 in the granulosa-lutein and endothelial cells of the entire corpus luteum. These studies confirm that in hyperstimulated animals as well as in mildly treated rats, VEGF and VEGFR-2 are overexpressed and associated with an increase in VP, which may be responsible for the accumulation of ascitic fluid in the syndrome.
We report five cases of first-trimester reversed end-diastolic flow in the umbilical artery. Diagnoses were performed between 8 and 12 gestational weeks. All but one case appeared as a transient early finding. Second-trimester fetal demise occurred in two cases. One case delivered at 32 weeks with severe growth restriction but recovered well. The other two cases had a good pregnancy outcome. Our experience suggests that this early Doppler finding is not always an ominous sign.
Chemokines are small polypeptides that attract specific leukocyte subsets by binding to cell-surface receptors. In reproductive biology, they have been implicated in ovulation, menstruation, and embryo implantation, and pathological processes such as preterm delivery, HIV infection, and endometriosis. It is known that successful implantation requires a functionally normal embryo at the blastocyst stage and a receptive endometrium that is adequately communicated through the implantation process. This crosstalk is highly regulated, with numerous molecules taking part. Accumulated evidence suggests that chemokines produced and received by the endometrial epithelium and the human blastocyst are implicated in this molecular network. Here, we present updated information on the presence and hormonal and embryonic regulation of chemokines and their receptors during human implantation.
Extended embryo culture together with amelioration of embryo selection methods and embryo culture conditions have allowed a substantial increase on both pregnancy and implantation rates. However, uterine embryo transfers are still performed after 2 to 6 days of egg retrieval. In this paper, we show the results of two studies, one prospective study comparing IVF outcome of day 2 and day 3 embryo transfers, and a retrospective study looking at blastocyst transfers versus day 3 embryo transfers in our egg donation program. Also, we test the predictive value of the presence of three or more seven cell-stage embryos on day 3 of development on blastocyst formation and pregnancy rates. No significant differences were found between day 2 and day 3 embryo transfers in terms of pregnancy, ongoing pregnancy, and implantation rates, as well as in multiple and in high order pregnancy. In general, day 6 embryo transfers resulted in significantly higher ongoing pregnancy and implantation rates compared with day 3 embryo transfers (41.1 per cent and 23.6 per cent versus 50.1 per cent and 38.1 per cent, respectively). No differences were found in terms of multiple gestations despite transferring significantly more embryos on day 3 compared with day 6 transfers. When less than three 7-cell embryos were present in the embryo cohort, day 6 embryo transfers did not improve the rates of ongoing pregnancy with regards to day 3 embryo transfer, although significant high implantation rates were obtained on the group of blastocyst transfer. The presence of three or more 7 cell-stage embryos improved significantly both ongoing pregnancy and rates on blastocyst transfers compared to day 3 embryo transfers (65.6 per cent versus 50.6 per cent and 37.4 per cent vs 24.7 per cent, respectively). In conclusion, at least in egg donation, day 3 embryo transfers do not improve either pregnancy or implantation rates when compared to day 2 transfers. Generally speaking blastocyst transfers give significantly higher chance of pregnancy and implantation rates per cycle and per transfer than early cleavage stage transfers. However, the absence of a good embryo cohort, that is having less than three 7 cell-stage embryos on day 3, blastocyst transfers will improve implantation rates but not ongoing pregnancy rates.
Implantation failure (IF) is defined as three or more failed IVF attempts, and preimplantation genetic diagnosis (PGD) is being used in these patients to improve IVF outcome. PGD was performed in 49 implantation failure patients with a mean number of 4.2 +/- 1.6 previous IVF failures, and in nine fertile controls. Fluorescence in-situ hybridization (FISH) on blastomeres from biopsied day 3 embryos was performed for chromosomes 13, 16, 18, 21, 22, X and Y. There was a significantly higher rate of chromosomal abnormalities (67.4%) compared with controls (36.3%). In 57 cycles, a pregnancy rate of 34.0% and an implantation rate of 19.8% was observed in implantation failure patients compared with controls (33.3 and 24.1% respectively), with all the pregnancies in the implantation failure group coming from the transfer of at least one chromosomally normal blastocyst on day 5. It is concluded that in IVF patients, use of PGD along with blastocyst transfer improves IVF outcome.
BACKGROUND: Chromosomal abnormalities are an important cause of spontaneous abortion and recurrent miscarriage (RM). Therefore, we have analysed the incidence of chromosomal abnormalities and embryo development in patients with RM. METHODS: Preimplantation genetic diagnosis (PGD) was performed on 71 couples with RM and 28 couples undergoing PGD for sex-linked diseases (control group). Chromosomes 13, 16, 18, 21, 22, X and Y were analysed by fluorescence in-situ hybridization. RESULTS: The implantation rate in RM patients was 28% and three patients (13%) miscarried. The percentage of abnormal embryos was significantly increased (P < 0.0001) in RM patients compared with controls (70.7 versus 45.1%). All of the embryos were abnormal in 19 cycles (22.1%) and repeated PGD cycles yielded similar rates of chromosomal abnormalities in 14 couples. Anomalies for chromosomes 16 and 22 were significantly higher (P < 0.01) in RM cases. In the RM population, euploid embryos reached the blastocyst stage more frequently than abnormal embryos (61.7 versus 24.9%; P < 0.0001). CONCLUSIONS: RM is associated with a higher incidence of chromosomally abnormal embryos, of which some are able to develop to the blastocyst stage. IVF plus PGD is an important step in the management of these couples, but the technique has to move towards a full chromosome analysis.
BACKGROUND: Patients persistently azoospermic after chemotherapy have been considered traditionally as sterile unless sperm was frozen before therapy. Recent advances during the last decade combining testicular sperm extraction (TESE) and ICSI in patients with non-obstructive azoospermia allow these males to father their own genetic offspring. METHODS: A retrospective study was conducted of 12 patients with non-obstructive azoospermia after chemotherapy undergoing TESE between 1995 and 2002. Cancer type and anti-neoplastic treatments were recorded, together with maximum testicular volume, serum FSH levels and testicular histopathology. When TESE was successful, spermatozoa were cryopreserved for performing ICSI later. RESULTS: In five patients (41.6%) motile spermatozoa for cryopreservation and ICSI were retrieved. Four of them had received chemotherapy for testicular cancer, and one had been treated by chemotherapy/radiotherapy for Hodgkin's disease. Clinical and histological parameters were unable to predict with certainty TESE outcome in an individual patient. Eight ICSI cycles were performed on five couples and one pregnancy was obtained which resulted in the delivery of a healthy girl. CONCLUSION: Some patients with permanent azoospermia after chemotherapy can be successfully treated by TESE-ICSI. This procedure, however, may have potential genetic risks. Therefore, freezing semen before starting gonadotoxic therapy is the strategy of choice, and patients should be counselled accordingly.
We know that the implantation process requires a functionally normal embryo at the blastocyst stage and a receptive endometrium, but also a communication link between them is needed. This paracrine dialogue between the embryo, endometrium and the corpus luteum are known to occur in ruminants and primates, more specifically endometrial-embryonic interactions have been reported in rodents and primates but not in humans. This process is a highly regulated mechanism and many molecules take part in this cross-talk. Here, we present updated information in humans on the embryonic regulation of endometrial epithelial molecules such as chemokines, adhesion and anti-adhesion molecules, and leptin during the apposition and adhesion phases of human implantation.
The process of embryonic implantation needs coordinated development and communication between the blastocyst and the maternal endometrium. Considerable advances in the understanding of the cell biology of the human embryo and maternal endometrium have been achieved separately. However, the communication between them, and the reciprocal effects on each other, constitute a complicated and yet unsolved question in reproductive medicine that must be further investigated. A paracrine dialogue between the embryo, endometrium and the corpus luteum is known to occur in other species such as rodents and primates. The aim of this work is to present updated information on the embryonic regulation of endometrial epithelial molecules such as adhesion molecules, anti-adhesion molecules, cytoskeletal proteins, chemokines and leptin during the apposition and adhesion phases of human implantation.
BACKGROUND: The main concerns for couples undergoing assisted reproduction treatment using donor gametes are the possibilities of acquiring infectious diseases and of transmitting genetic disorders to the progeny. They are also frequently concerned and interested in the cultural and psychological background of the donors. Our aim was to examine the current prevalence of genetic alterations and infectious diseases in our sperm and oocyte donor population, and to review our experience in the management of donors and candidates during the last 10 years. METHODS AND RESULTS: Routine blood analyses, semen and vaginal cultures together with complete medical, psychological and genetic histories were examined retrospectively. Our results clearly show that the frequency of sexually transmitted diseases and genetic disorders is comparable with both the frequency present in the population requiring infertility treatments and the general population. CONCLUSIONS: The screening procedure applied to all the candidates sufficiently minimizes any risk to the gamete receiver and the offspring.
BACKGROUND: Oocyte donation provides us with an opportunity to study the clinical outcome of oocytes, retrieved from women undergoing coasting, in recipients in whom endometrial receptivity is unaltered by the coasting procedure. Thus, our aim was to describe oocyte donation outcome in donors undergoing coasting, the oocyte and embryo quality obtained from these cycles, and to determine the influence of coasting duration in the cycle outcome. METHODS: Matched-paired analysis included 15 oocyte donors with high response to ovarian stimulation and submitted to coasting and 15 oocyte donors with normal response to ovarian stimulation and not undergoing coasting. There were 38 oocyte recipients who shared oocytes from the donors under coasting and 37 from donors not undergoing coasting. RESULTS: Both groups of donors were comparable in terms of days and dose of ovarian stimulation, oocytes retrieved, metaphase II oocytes obtained, and in the appearance of ovarian hyperstimulation syndrome. Both groups of oocyte recipients were comparable in male-associated factor, pregnancy and implantation rates, as well as in embryo quality. Recipients from donors with coasting for >4 days had significantly lower implantation and pregnancy rates. CONCLUSIONS: the outcome of oocyte donation from donors undergoing coasting is not impaired, as good implantation and pregnancy rates are achieved. Embryo quality, according to our current standards, does not seem to be compromised by coasting itself. However, if coasting in oocyte donors is prolonged for >4 days there is a significant decrease in both implantation and pregnancy rates.
Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication of treatment with fertility drugs. Using human lung microvascular endothelial cells (HUMEC-L) as an in-vitro model of OHSS, we have tested the hypothesis that the endothelium is a target of HCG in the pathogenesis of OHSS. Since OHSS is characterized by increased capillary permeability, we have investigated the production and action of vasoactive agents. When HUMEC-L were cultured with high doses of estradiol (E(2)), no significant changes were observed in the secretion of vascular endothelial growth factor (VEGF), interleukin (IL)-6 or IL-1 beta. However, the addition of HCG resulted in a significant increase in the secretion of VEGF and IL-6. Time-course experiments showed that VEGF was secreted within minutes of HCG addition, whereas IL-6 was significantly increased only after 48 h in culture. The secretion of IL-1 beta was unchanged by these hormonal conditions. The presence of HCG receptors was demonstrated in HUMEC-L in basal conditions as well as after the addition of E(2). The expression of VEGF receptors was also investigated. High doses of E(2) were unable to increase the expression of KDR, flt-1 and sfl-t, but the addition of HCG significantly upregulated the KDR concentration in endothelial cells, while no change was observed for flt. Permeability assays demonstrated that while E(2) alone did not change the arrangement of HUMEC-L in vitro, the presence of HCG caused changes in the actin fibres corresponding to increased capillary permeability. Anti-human VEGF antibodies were able to overcome these changes. In conclusion, these experiments show that the endothelium may be a primary target of HCG, causing an acute release of VEGF and a significant increase in IL-6 and resulting in an autocrine-paracrine action that may increase vascular permeability.
Flow cytometry (FC) is an analytical cytology technique which has been extensively used for decades. It has many advantages compared with other similar methods for the study of cell biology, even on a molecular basis. FC allows the cell-by-cell analysis of many optical or immunological features in the same sample, at the same time, and at a rate of thousands of cells per second, generating immense quantities of data and thus providing almost limitless information which is statistically robust due to the number of units studied. The aim of this review is to describe the contribution of FC to the study of physiological and pathological processes related to human reproduction, and to discuss how this technique has been used in research, as well as its clinical applications in this field. We have used some practical examples selected from the most relevant studies within a wide range of investigations published in the literature, and we have also drawn on our own experience of using flow cytometry to study different phenomena related to reproduction. It is conclued that FC is a useful instrument for basic investigation of gynecological issues, as well as for the study of male reproductive characteristics, either in research applications or directly for clinical diagnostic purposes. Future development of these techniques will permit further advances both in our knowledge and in the improvement of assisted reproduction techniques.