PubMed Health⌕ Search

Biomedical subjects

Juan A Garcia-Velasco

Publications and source records attributed to Juan A Garcia-Velasco.

15 recordsLinked to original sources
PubMed2005

The aromatase inhibitor letrozole increases the concentration of intraovarian androgens and improves in vitro fertilization outcome in low responder patients: a pilot study.

OBJECTIVE: To evaluate the impact of aromatase inhibitors as adjuvant treatment in IVF cycles on intraovarian androgens and cycle outcome. DESIGN: Observational, pilot study. SETTING: University-affiliated IVF unit. PATIENT(S): One hundred forty-seven low responder patients with a previous canceled IVF cycle; 71 patients were treated with letrozole 2.5 mg plus a high-dose FSH/hMG-antagonist regimen, and 76 patients were similarly treated but letrozole was not employed. INTERVENTION(S): In vitro fertilization treatment with an antagonist FSH/hMG protocol with or without letrozole was administered during the first 5 days of stimulation; hormones were evaluated in both serum and follicular fluid. MAIN OUTCOME MEASURE(S): Number of oocytes retrieved, fertilization rate, implantation rate, and pregnancy rate; androstenedione, T, E2, and P values in serum and follicular fluid. RESULT(S): Letrozole-treated patients showed significantly higher levels of follicular fluid T and androstenedione (80.3 vs. 43.8 pg/mL and 57.9 vs. 37.4 mg/mL, respectively). Similarly, these patients had a higher number of oocytes retrieved (6.1 vs. 4.3) and a higher implantation rate (25% vs. 9.4%) despite similar doses of FSH/hMG (3,627 vs. 3,804 IU). CONCLUSION(S): Adding 2.5 mg of letrozole to a high-dose FSH/hMG antagonist protocol increases intraovarian androstenedione and T concentration and improves IVF cycle outcome in poor responder patients.

Adult↗
PubMed2005

How would revealing the identity of gamete donors affect current practice?

The possibility of revealing the identity of gamete donors may change the decision of a donor to collaborate with infertility clinics and patients. Previous experiences with patients and donors, as well as different cultural viewpoints in northern and southern Europe, are presented.

Confidentiality↗
PubMed2004

Removal of endometriomas before in vitro fertilization does not improve fertility outcomes: a matched, case-control study.

OBJECTIVE: To investigate whether conservative surgery on ovarian endometriomas before an IVF cycle improves fertility outcomes. DESIGN: Retrospective, matched case-control study. SETTING: Two academic IVF programs. PATIENT(S): One hundred eighty-nine women with endometriomas who underwent IVF treatment: 56 women proceeded directly to IVF, and 133 first underwent conservative ovarian surgery. INTERVENTION(S): Controlled ovarian hyperstimulation and IVF-ET. MAIN OUTCOME MEASURE(S): Response to gonadotropins, fertilization, implantation, and pregnancy rates. RESULT(S): Aside from lower peak E(2) levels on the day of hCG and a higher total FSH dose in women previously operated for an endometrioma, no significant differences were found between the two groups in the different IVF variables analyzed. CONCLUSION(S): Laparoscopic cystectomy for endometriomas before commencing an IVF cycle does not improve fertility outcomes. Proceeding directly to controlled ovarian hyperstimulation in women with asymptomatic ovarian endometriomas might reduce the time to pregnancy, the costs of treatment, and the hypothetical complications of laparoscopic surgery. Conversely, conservative surgical treatment of ovarian endometriomas in symptomatic women does not impair IVF or intracytoplasmic sperm injection success rates.

Adult↗
PubMed2003

Factors that determine discordant outcome from shared oocytes.

OBJECTIVE: To investigate the factors that may be related to pregnancy in oocyte recipients who shared oocytes from the same donor and showed discordant pregnancy outcome. DESIGN: Matched pair analysis. SETTING: IVF academic center. PATIENT(S): Five hundred forty-two oocyte donation cycles that shared oocytes from 197 donors with discordant outcome. INTERVENTION(S): Egg donation and embryo transfer. MAIN OUTCOME MEASURE(S): Pregnancy rate and implantation rate. RESULT(S): Three hundred sixty-five matched-paired discordant outcome oocyte recipients were analyzed. Pregnant and nonpregnant recipients were similar in terms of age, serum E(2) levels, endometrial thickness, indications for oocyte donation, and abnormal sperm parameters. No differences were found in the number of oocytes received per patient, fertilization rate, IVF/intracytoplasmic sperm injection (ICSI) distribution, embryo quality, or on embryo transfer difficulty. CONCLUSION(S): Discordant pregnancy outcome could not be explained by the different egg recipients and cycle factors studied. In addition to chance, other factors must be investigated that could explain discordant outcome in egg recipients sharing oocytes from single donors.

Adult↗
PubMed2003

Clinical experience and perinatal outcome of blastocyst transfer after coculture of human embryos with human endometrial epithelial cells: a 5-year follow-up study.

OBJECTIVE: To evaluate the reproductive and neonatal outcome of blastocyst transfer after coculture with human endometrial epithelial cells in IVF and oocyte donation. DESIGN: Retrospective study. Private assisted reproductive center. PATIENTS(S): Two hundred sixty women undergoing IVF and 469 oocyte recipients. INTERVENTION(S): IVF or intracytoplasmic sperm injection (ICSI) and transfer of at least one blastocyst after coculture with human endometrial epithelial cells. MAIN OUTCOME MEASURE(S): Blastocyst formation rate, implantation and pregnancy rates, neonatal outcome, and congenital birth defects. RESULT(S): Among patients who had transfer with their own oocytes, 1193 of 2349 cocultured embryos developed up to the blastocyst stage (50.8%), and pregnancy and implantation rates of 33.9% and 19.2%, respectively, were achieved. In the oocyte donation program, 1819 blastocysts were obtained from 3127 embryos (58.2%), with subsequent pregnancy and implantation rates of 57.0% and 31.0%, respectively. The blastocyst rate remained stable throughout the 5 years of the study, but the pregnancy and implantation rates increased dramatically. Of 139 deliveries, 57 (41.0%) were multiple pregnancies and 1 (0.7%) was a multifetal birth (four live born infants). Out of 200 children born, 59% were male, and congenital birth defects were observed in 2.5%. CONCLUSION(S): Coculture of human embryos with endometrial epithelial cells yields a blastocyst formation rate of 50.8% to 58.2% and encouraging implantation and pregnancy rates. This technique reduces the mean number of embryos transferred in each patient. The number of embryos implanted is more relevant to neonatal outcome than is the coculture system and blastocyst transfer used. The risk of congenital birth defects associated with this program is similar to that recorded in early ET in IVF or ICSI.

Adult↗
PubMed2003

Apoptosis and the pathogenesis of endometriosis.

Apoptosis is a physiologic process that deletes unwanted cells without inducing an inflammatory reaction. Survival of endometriotic implants is associated with decreased apoptosis and an inflammatory environment. The most widely accepted theory-transplantation theory-related to the pathogenesis of endometriosis is supported by the description of abnormal survival of regurgitated endometrial cells. Eutopic endometrial cells from women with endometriosis also seem to resist apoptosis further when compared with cells from disease-free women. Several apoptotic pathways have been studied. Recent literature concerning apoptosis-related genes such as bcl-2/bax and fas/fas ligand is summarized in this article. Special emphasis is placed on sex steroid modulation and cell adhesion regulation, both relevant in early events of endometriosis.

Apoptosis↗
PubMed2003

New concepts in the understanding of the ovarian hyperstimulation syndrome.

PURPOSE OF REVIEW: In this review we will evaluate the recent developments in the pathophysiology of the ovarian hyperstimulation syndrome, with special emphasis on mediators of human chorionic gonadotropin action. RECENT FINDINGS: From all the different molecules investigated, it seems that vascular endothelial growth factor is the key mediator of human chorionic gonadotropin action on the vascular tree. Recent data show that although absolute serum vascular endothelial growth factor values are useless in predicting the occurrence of ovarian hyperstimulation syndrome, individual variations in binding profiles may account for clinical differences. It has been shown that vascular endothelial growth factor is produced, expressed and secreted in the ovary and that it mediates vascular permeability in response to human chorionic gonadotropin in a time-dependent fashion. This effect may be blocked by a synthetic compound (SU5416) developed to inhibit its high-affinity receptor, kinase domain containing receptor signaling in different cancers by avoiding the initial phosphorylation of vascular endothelial growth factor receptor-2. SUMMARY: Vascular endothelial growth factor is a promising molecule in the understanding of ovarian hyperstimulation syndrome. Future treatments should be directed to modulate or inhibit its action on the vascular wall.

Chorionic Gonadotropin↗
PubMed2002

Estradiol down-regulates MCP-1 expression in human coronary artery endothelial cells.

OBJECTIVE: To determine whether estrogen down-regulates MCP-1 in vascular endothelial cells. DESIGN: A prospective comparative study. SETTING: Academic research environment. PATIENT(S): Human umbilical vein endothelial cells (n = 3) and human coronary artery endothelial cells (n = 3) obtained from females. INTERVENTION(S): Human umbilical vein endothelial cells (HUVEC) and human coronary artery endothelial cells (HCAEC) were grown to preconfluence. Then, they were treated with various concentrations of estradiol (10(-11) M to 10(-7) M) as well as raloxifene (10(-7) M) and tamoxifen (10(-7) M). MCP-1 in culture media was quantified using an enzyme-linked immunosorbent assay (ELISA). Cellular ribonucleic acid (RNA) was extracted and Northern blots were hybridized with an oligonucleotide probe complementary to a specific sequence of MCP-1 mRNA. MAIN OUTCOME MEASURE(S): MCP-1 protein and mRNA. RESULT(S): Estrogen treatment did not change MCP-1 expression in HUVEC. On the other hand, in HCAEC, estradiol induced a 30% decrease in mRNA expression and resulted in dose-dependent inhibition of MCP-1 production as detected by ELISA. Raloxifene and tamoxifen also resulted in inhibition of MCP-1 mRNA and protein expression. CONCLUSION(S): Our findings suggest that one of the mechanisms by which estrogen down-regulates atherosclerosis is by suppressing vascular MCP-1 expression, resulting in decreased macrophage recruitment.

Blotting, Northern↗
PubMed2002

Elevated soluble Fas ligand levels may suggest a role for apoptosis in women with endometriosis.

OBJECTIVE: To evaluate soluble Fas ligand concentrations in serum and peritoneal fluid from women with endometriosis and from fertile controls without endometriosis, and to study levels of soluble Fas ligand in conditioned media of cultured endometrial stromal cells. DESIGN: Prospective, experimental trial. SETTING: Two academic IVF centers. PATIENT(S): Twenty-nine fertile women without endometriosis and 57 infertile women with endometriosis (32 with stage I or II disease and 25 with stage III or IV disease). MAIN OUTCOME MEASURE(S): Enzyme-linked immunosorbent assay was used to measure soluble Fas ligand concentrations in paired samples of serum and peritoneal fluid from women with and without endometriosis. Concentrations were also measured in conditioned media of cultured endometrial stromal cells at basal conditions and after stimulation with interleukin-8 (0.001-10 ng/mL) and tumor necrosis factor-alpha (1-10 ng/mL). RESULT(S): Compared with fertile controls and women with early-stage of endometriosis, women with moderate to severe endometriosis had elevated serum (87.2 +/- 6.4, 88.2 +/- 6.9, and 162.3 +/- 7.8 pg/mL, respectively) and peritoneal fluid (81.0 +/- 6.0, 80.5 +/- 6.8, and 166.2 +/- 10.3 pg/mL, respectively) concentrations of soluble Fas ligand. Serum levels of soluble Fas ligand positively correlated with levels in peritoneal fluid. Comparison of patients in the same menstrual cycle in each group revealed that increased levels of soluble Fas ligand in patients with advanced endometriosis were not attributable to the difference in cycle phases. Soluble Fas ligand was not detected in conditioned media of endometrial stromal cells under baseline conditions or after stimulation. CONCLUSION(S): Serum and peritoneal fluid of women with moderate to severe endometriosis contain elevated concentrations of soluble Fas ligand compared to women with minimal or mild endometriosis and women without endometriosis. These findings suggest a role for apoptotic dysregulation in the pathophysiology of endometriosis.

Apoptosis↗
PubMed2002

Extracellular matrix-dependent regulation of Fas ligand expression in human endometrial stromal cells.

Interaction between endometrial stromal cells and extracellular matrix (ECM) components has a crucial role in the development of endometriosis. Endometrial stromal cells attach to the mesothelial surface of peritoneum by means of integrins during their initial implantation and growth in endometriosis. Similarly, interaction between integrin and the extracellular matrix is also crucial for the remodeling of the endometrium during early pregnancy. We hypothesized that adhesion of endometrial stromal cells to the extracellular matrix could suppress the immunologic reaction to implanting endometrial cells by inducing the expression of Fas ligand (FasL), a mediator of the apoptotic pathway. Western blot analysis of human endometrial stromal cells plated onto fibronectin, laminin, and collagen IV revealed higher levels of FasL protein expression compared with endometrial stromal cells that plated to BSA-coated plates (control). Immunocytochemistry results from endometrial stromal cells plated to extracellular matrix proteins demonstrated a similar up-regulation of FasL expression. Eutopic endometrial stromal cells from women with endometriosis demonstrated higher FasL expression on control plates and those coated with extracellular matrix proteins compared with those from women without endometriosis. Disruption of actin cytoskeleton in endometrial stromal cells by treatment with cytochalasin D blocked the increase of FasL protein expression that occurred in response to adhesion to the extracellular matrix. These results suggest that attachment of endometrial stromal cells during retrograde menstruation to a new environment such as peritoneum with increased expression of laminin, fibronectin, and collagen IV could lead to an increase in FasL expression. Induction of FasL expression by adhesion of endometrial stromal cells to the extracellular matrix may take part in the development of a relative immunotolerance by inducing apoptosis of cytotoxic T lymphocytes, which will allow further development of ectopic implants.

Adult↗
PubMed2002

Regulation of fas ligand expression by IL-8 in human endometrium.

Numerous cytokines and growth factors are synthesized in the endometrium. IL-8 is one of these cytokines regulating endometrial function. It is a neutrophil chemoattractant/ activating factor and a potent angiogenic agent. IL-8 is elevated in the peritoneal fluid of women with endometriosis. We have previously demonstrated a direct proliferative effect of IL-8 on endometrial stromal cells. We hypothesized that increased levels of IL-8 in the endometriotic environment could up- regulate Fas ligand (FasL) expression in endometrial cells and may be relevant for the development of a relative local immunotolerance in endometriosis by inducing apoptosis of cytotoxic T lymphocytes. To test our hypothesis, we studied the in vitro regulation of FasL expression and apoptosis by IL-8 in endometrial cells. Western blot analysis in endometrial stromal, glandular, and Ishikawa cells revealed that IL-8 up- regulated FasL protein expression in these cells. By semiquantitative RT-PCR analysis, IL-8 does not alter the expression of either Fas or FasL mRNA levels in these cells. Immunocytochemistry results from endometrial stromal cells treated with IL-8 demonstrated an up-regulation of FasL protein expression. IL-8 decreased apoptosis rate in endometrial stromal cells as evaluated by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assay. We observed an increased apoptotic rate in Jurkat (T lymphocyte line) cells plated on endometrial stromal cells previously treated with IL-8. We speculate that increased FasL expression by IL-8 may induce apoptosis of T lymphocytes and thus produce a local immunotolerant environment for the development of ectopic implants.

Adult↗